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Wireless Ethernet LAN Adaptor

1. Vv Increment byte_Ptr _ Finished the n whole b ter a Yes D 11 Figure D 7 Flow Chart for Disassemble Function D 2 5 2 Flow Chart for the Assemble Function Figure D 8 shows the flow chart for the assemble function in the copy routine C State Idle Vv gt Find next unprocessed BD in BD tablea Is BD is the first BD for new packet Yes v Allocate Ethernet Tx Buffer N Set Current_Packet_Length O Q Set Ethernet Tx_Buffer_Ptr to Serial Rx_Byte_Ptr No Vv Increment Serial Rx_Byte_Ptr by gt Ethernet Rx_Byte_Length of unprocessed BD Yes Increment Current_Packet_Length by Serial Rx_Byte_Length of unprocessed BD Does received data contai end of packet sequence Yes y Set Ethernet Tx_Buffer_Length to Current_Packet_Length No S Packet Sent by Etherne Port Figure D 8 Data Flow Diagram for Assemble Function D 12 D 2 6 SYSTEM INITIATION During startup of the WELA system a script will be run to initialize the system First it will initialize the stack pointer and the interrupt vector table After which the Ethernet Initialization sequence and Serial Initialization sequence will be ran Lastly the pointers used by the Copy Module will be initialized the Rx interr
2. Assemble A Ethernet ISR Senalion 10 Tx Ethernet Tx_Data Rx_Data Cleanu 1 Rx Disassemble Serial Cleanup Ethernet Packet Buffer Serial Data Buffer Figure D 4 Transmission of a Packet from Ethernet to Serial port The following sequence happens to process the data packet until it is transmitted out of the serial interface i 2 3 10 Data packet is received into the receive FIFO queue CPM moves the data from the FIFO queue into the Ethernet receive buffer CPM generates an Ethernet interrupt to trigger Ethernet Receive ISR The ISR increments the disassemble status variable to indicate that there is one more packet ready for disassemble The copy module is constantly checking for the disassemble status variable When the status variable indicates that there is unprocessed packet the disassemble function will attempt to locate the unprocessed packet buffers are process based on a FIFO scheme This is done by checking the BD that is pointed by the Current_Unprocessed_Ethernet_RX_Ptr of the Ethernet RX BD table Once the unprocessed packet is located the disassemble function reads in the packet length and the starting location in the memory The disassemble function calculates the amount of serial TX BDs needed to transmit the Ethernet packet It will setup the serial TX BDs to point to each
3. It is an ARP message which has been replied when ARP_Init function was called call eth_setRxBufferEmpty FoundARP FALSE RxPtrFound FALSE Check to see if a Serial Packet is waiting for assemble if Serial_Rx_Ptr ser_recv amp Serial_Rx_Length NULL Function twoByteToHex is used to convert ASCII into HEX call twoByteToHex tempbuff Serial_Rx_Ptr function Serial_Rx_Ptr tempbuff if Eth_Tx_Ptr NULL call Assemble function ser_setRxBufferEmpty SerRxPtrFound FALSE return 0 3 2 1 1 DISASSEMBLE BLOCK Function Disassemble CopyToSer Serial_Tx_Ptr Eth_Rx_Ptr Eth_Rx_Len 4 for the four end of sequence bytes ser_send Eth_Rx_Lent4 eth_setRxBufferEmpty End Disassemble 3 2 1 2 ASSEMBLE BLOCK Table 5 Description of Local Variables used in Assemble Function Variable Name Description int End Indicate end position of the packet int Start Indicate start position of the packet int Length Indicate length of the packet Function Assemble 29 loop until Previous_Length Start 0 amp amp Start lt Serial_Rx_Length 1 Search Start End End_Of_Sequence_Found Serial_Rx_Length Length End Start 1 CopyToEth Eth_Tx_Ptr Previous_Length Serial_Rx_Ptr Start Length This condition is for the Ethernet Packet fits inside the
4. Figure 1 Transmission of a Packet from Ethernet to Serial portt v cisninisnnianinnsiotain 18 Figure 2 Transmission of a Packet from Serial to Ethernet Port ssssssssssesseessseesseesseesseeereesreess 20 Figure 3 Flow Chart for Copy Modulessnisdsssssisednsesdin anandia i a 23 Figure 4 Flow Chart for Disassemble Function seessssssseesseesseesseesseesstessreseresereserenereneeenerenresneese 24 Figure 5 Flow Chart for Assemble Function ssesssesssssesseesseesseesseesseessressressresteesereneeeneeeneeenresnese 26 Pipe C 1r Overall System Architect Es sne aa aa C 2 Pisnte D T Top kev l System metal ccinavatonianisntiavn i E E A a AT D 1 fos beg oes D 2 Top Leyel Struct r Ob fea 2c sissi ra ia ii EEE EA EE terete crores N pi ia D 3 Figure D 3 System Event Diao taan i ce Gets ccy csi seal yestuestcaseaisaageasvaneerstraianed a eo ets D 5 Figure D 4 Transmission of a Packet from Ethernet to Serial port cccsesseseeeseeseeen D 6 Figure D 5 Tranmission of a Packet from Serial port to Ethernet 0 D 8 Figure D 6 Block Diagram for Copy Module cis vnistitesteriesoainerers leavers vatneis venmaia onineiatomitiars D 10 Figure D 7 Flow Chart for Disassemble Function gaint iioittatieininlinisidinstdieisinaien sind D 12 Figure D 8 Data Flow Diagram for Assemble Function sse ssesssesersssressrressresreesereseeesereneess D 12 Figure D 9 GetLocallP Procedure Diagram viimuicniitaninim din aneitonunanniteds D 14 Figure D 1
5. Initialize Initialize Ethernet Interface Copy Block Serial Interface 6 Return Ptr Assemble Ethernet ISR Serial ISR CPM 5 amp 14 Get Tx Buffer Ethernet 2 amp 3 Cleanup Get Ready Serial Buffer a a Tx_Data 11 Call 1 Rx_Data _ 12 Tx 4 Return Ptr Disassemble 13 Done 10 Ready C 8 Call Send 9 Link to a WEBy Packet Eihomet packet Serial Data Buffer Buffer Figure 2 Transmission of a Packet from Serial to Ethernet Port The following sequence happens to process the data packet until it is transmitted out of the Ethernet interface ts Data packet is received into the serial receive FIFO queue 2 Copy module will usually be inside ser_recv 3 ser_recv polls the status bit in serial interface and copies to serial Rx buffer until 20 10 11 12 13 14 EOS is detected At this point ser_recv returns to Copy module Copy module receives a non NULL pointer to serial Rx buffer Therefore it will convert ASCII characters back to binary and calls Assemble function Assemble function calls eth_getTxBuffer to get a pointer to the next available Ethernet Tx buffer eth_getTxBuffer returns the next free Tx buffer and increments its own Tx buffer index This is the buffer which CPM will be checking for ready bit Assemble
6. Under limited resources and support we are still able to meet most of the milestones The following section lists the milestones we have achieved and missed at sign off time 2 2 ETHERNET MODULE 2 2 1 MILESTONES ACHIEVED For the Ethernet module the Ethernet controller can be enabled to trigger interrupts and make the sending and receiving process fully interrupt driven Furthermore the prototype is able to receive incoming Ethernet packets and transmit Ethernet packets from the Motorola board To ensure 100 Ethernet compatibility with existing network the interface of the prototype must be able to update the host s Address Resolution Protocol ARP table with its IP address The Ethernet module was able to respond to ARP requests from the host and reply to PC with the updated hardware address 2 2 2 MILESTONES MISSED In the original design the Ethernet adaptor was designed to update its own IP address with the IP address of the remote PC s IP address This is necessary in order to achieve truly plug and play installation of the Ethernet adaptor However since setting up the interrupts and the Communication Processor Module CPM on the MBX860 turns out to be much more complicated than imagined implementing the automatic IP update feature in the design cannot be accomplished with insufficient time For now the remote PC s address is hard coded in the software code To change the IP the software must be re compile 2 2 3 MOD
7. 100 trials and take the average The bit error rate can be verified after ensuring Ethernet network compatibility the transmission rate and the transmission distance requirements are met The following will be performed 1 Move Computer A and Computer B 25 meters apart Setup Ethernet connection between Computer A and Computer B using the prototypes 3 Runa program that will send a stream of data from Computer A to Computer B Computer B will have another program running to count the number of data bits that are incorrect The bit error rate is the total incorrect data bits divided by total data bits received 4 Repeat step three 100 trials and take the average The packet error rate can be verified after the Ethernet network compatibility the transmission rate and the transmission distance requirements are met To ensure packet error rate of 2 the following will be performed 1 Move Computer A and Computer B 25 meters apart Setup Ethernet connection between Computer A and Computer B using the prototypes 3 Runa program that will send a stream of data from Computer A to Computer B Computer B will have another program running to check the checksum of the packet If the checksum is incorrect then the data in the received packet has error 4 Repeat step three 100 trials and take the average The transceiver output power can be verified in the E amp CE Microwave Lab The following will be performed 1 Setup Ethernet connect
8. 3 EXPECTED KNOWN REQUIREMENTS Table B 3 Expected or Known Requirements of the Project Requirements Needed Comments Lab Space Microwave lab We required using the Microwave lab to do measurement of the wireless transceiver We have made arrangements with the associated about the use of the lab and permission has been granted Equipment Power meter or spectrum analyzer We need a power meter or spectrum analyzer to measure the RF output power of the transceiver to see if it satisfies the customer requirements The equipment can be found in the Microwave lab DC power supply Also we need two DC power supplies to power up the two Motorola MBX Evaluation board We have acquired one power supply and will request the second one from the Lab technician once we get the second Evaluation board Transceiver We have ordered a pair of transceivers from RF Digital Corporation The cost of the transceiver will be taken from the budget allocated for the budget Motorola MBX Evaluation Board We need two MBX Evaluation Boards for the implementation of the design project The board will serve as the prototypes We currently got one of the board and now urgently requesting for the second board B 5 Software Embedded Development Kit EDK The EDK is needed because it is an essential tools to compile and assemble the code that is executed by the Motorola MBX Evaluatio
9. Module Description Module Description Serial_Interface The Serial ISR Block is used to service interrupts generated by events related to the serial port Whenever new data is received from the serial port an interrupt will be generated after the new data is copied to a buffer Ethernet_Interface The Ethernet ISR Block is used to service interrupts generated by events related to the Ethernet port When new data is recetved from the Ethernet port an interrupt will be generated after new data is copied to a buffer Copy_Block The Copy Block is used to coordinate the data manipulation between the Ethernet port and the serial port For data coming in from the Ethernet port stored in Ethernet BD it will disassemble the packet into smaller serial port packet For data coming in from the serial port stored in serial buffer it will reassemble the packet into larger Ethernet port packet Initialization The Initialization block is used to set up and initialize all global data structures D 2 3 TRANSMISSION OF DATA FROM ETHERNET TO SERIAL INTERFACE Figure D 4 shows the different interactions of the components listed in Table D 1 when a data packet comes in from the Ethernet interface System Ethernet_Serial_System from Ethernet to Serial pe Initialize Initialize Initialization Status 8 Update t initialize Decrement Ethernet Interface Copy Block Serial Interface
10. Pointer gt Rx Buffer Figure D 10 Buffer Structure D 16 D 3 1 2 Addition data structure Transmit Buffer Descriptor typedef struct Tx_BD_t Control Bits bool ready flag to indicate data ready for transmission 0 buffer does not contain data need to be transmitted can be used to store new transmission data 1 buffer contains data need to be transmitted bool wrap flag to indicate last BD in Tx_BD table 0 buffer is not the last BD 1 buffer is the last BD bool interrupt flag to indicate interrupt generated after BD is processed 0 no interrupt generated 1 interrupt generated Data Length Bits int data_length 16 bits to indicate the length of data in buffer pointed by BD Buffer Pointer Bits int Tx_buffer_high_ptr 16 bits to indicate the higher order bits of starting address of the data in buffer pointed by BD int Tx_buffer_low_ptr 16 bits to indicate the lower order bits of starting address of the data in buffer pointed by BD Tx_BD Receive Buffer Descriptor typedef struct Rx_BD_t Control Bits bool empty flag to indicate new data received 0 buffer is not empty contain new data that has not been processed 1 buffer is empty can be used to store new received data D 17 bool wrap flag to indicate last BD in Rx_BD table 0 buffer i
11. Serial Buffer if End_Of_Sequence_Found Notify Ethernet side that this packet is ready th_send Length Previous_Length Previous_Length 0 End_Of_Sequence_Found 0 Start End 5 End of sequence takes up 4 bytes The Ethernet packet spans more than 1 Serial Buffer else if End_Of_Sequence_Found Previous_Length Serial_Rx_Length Start ser_setRxBufferEmpty For cases when the Ethernet packet length is the same as the Serial Buffer size if Start gt Serial_Rx_Length 1 ser_setRxBufferEmpty 3 2 2 ETHERNET FUNCTIONS 3 2 2 1 ARP_INIT void ARP_init if received packet is ARP request packet loop until get an Ethernet Tx Buffer Fill the Buffer with the ARP header and destination address call eth_send to send out the packet set the Ethernet Rx Buffer to empty 30 3 2 2 2 ETH_INIT void eth_init initialize BD setup interrupt initialize SCC1 3 2 3 SERIAL FUNCTIONS 3 2 3 1 SER_SETRXBUFFEREMPTY FUNCTION Function ser_setRxBufferEmpty This function just set the flag ser_RxBufferPoolEmpty to TRUE if the flag ser_RxBufferPoolEmpty is FALSE if ser_RxBufferPoolEmpty ser_RxBufferPoolEmpty TRUE 3 2 3 2 SER_GETTXBUF FUNCTION Function ser_getTxBuf If the flag ser_TxBufferPoolEmpty is not empty it means that the previou
12. and budget All members Completed find sponsors 3 Dec 1 2000 End of Dec Develop initial system design All members Completed 2 X 3 og finalize requirements and specifications 4 Beginning of End of Jan Decide on which FPGA and All members Decided to use Jan 2001 SA transceiver to use Motorola board 5 Middle of Jan End of Jan Develop handshaking All members No longer part 2001 2001 i sae algorithm to avoid collisions of the customer on wireless channel requirement 6 Middle of Jan End of Jan Investigate possible All members No longer in 2001 2001 customer encryption schemes requirement 7 Beginning of End of Feb Develop algorithm for All members No longer in Feb 2001 2001 oe see o9 rettieving sending contents customer lt requirement between wireless transceiver and FPGA 8 ae of au of Feb Finalize design and order All members Ordered required components Motorola board and some sample National chips transceiver not received yet 9 May 01 2001 May 5 2001 Revise customer requirements All members Completed due week 2 10 April 20 2001 May 7 2001 Power up Motorola board and All members Completed verify PC can communicate with debug console 13 11 May 7 2001 May 14 2001 Verify PC can ping Ethernet Embedded Completed port of Motorola board and oe investigate how to control the Brhermet Ethernet port mod le 12 May 01 2001 May 11 200
13. and connect transceiver B to PC Some B s console packet 2 Type characters on PC A The same content characters should appear on PC B received on PCB ate shifted by half a byte but some packets are Okay System All 1 Same setup as NULL modem test Fail integrated except use transceivers to connect to Since the test serial port instead of NULL modem transceiver cable fails its 2 PC A s ping packet content should unit test show on PC B As shown in the above Table 9 the basic functionality of the design is met However at the present the interest time total optimisation for the prototype has not been completed and thus with of the customers in mind it is not wise to move onto full scale manufacturing level deployment as of now Nevertheless if given more time to fully optimise and to perform ex tensive testing on the design it can prove to be a successful product The following lists the areas that should be improved before full scale deployment The performance of the design can be increased significantly if the serial interface can be implemented to be fully interrupt driven The polling approach is inherently slow and there is a possibility that if the program does not poll fast enough some serial bytes might be lost The current implementation makes use of COM1 the console port instead of COM2 This is not the ideal port to use since access to any debugging messages is lost if
14. function copies data from serial Rx buffer to Ethernet Tx buffer The Assemble function calls eth_send to send data The Assemble function will link the data in the serial RX BD into a packet eth_send sets the ready bit of the Ethernet Tx BD to indicate to the CPM that the packet is ready for transmission The CPM will move the ready Ethernet TX BD s packet to the FIFO queue for transmission The ready bit of the Ethernet TX BD will be automatically cleared by the CPM after the packet is moved to the FIFO queue The packet will get transmitted through the Ethernet interface eth_send returns to Assemble function Assemble function now calls set_serRxBufferEmpty to indicate to serial module that it has finished using the current Rx buffer eth_send calls eth_getTxBuffer to get a new Ethernet Tx buffer to prepare for next transmission 3 1 3 BLOCK DIAGRAM FOR THE COPY MODULE Figure 3 shows the flow chart of the Copy Module The Copy Module consists of five main functions Disassemble CopyToSerial Assemble CopyToEth and Search When new data packets arrive from the Ethernet port the disassemble function will partition the packets into smaller packets so that they can be handled by the serial interface 21 After all the smaller partitions of an Ethernet packet are sent it will call eth_setRxBufferEmpty to set the empty bit of the Ethernet receive buffer When new data arrive from the serial port the assemble fu
15. order to make it into half or full duplex more components and development are needed 3 This was completely unexpected and time has not been allocated for this purpose It is strongly believed that making the transceivers functional will require a vase amount of time since care must been taken to avoid noise and distortion of signals when inserting additional circuits Although getting the transceiver to work is important many difficulties encountered during the development phase when working with another more vital part of the design the Motorola Board required the focus of the whole team and thus prevented putting more time into the transceiver Thus at the end testing of the transceivers cannot be completed 2 5 3 MODIFICATIONS AND JUSTIFICATIONS The wireless transceiver needs additional circuitry to make it half duplex However this modification has not been made yet The transceiver can transmit data but the bytes are 12 shifted by half a byte This behaviour does not occur when a NULL modem cable connection was used Therefore additional modifications to the code are required to compensate for this shift Table 2 summarizes the design milestones achieved and missed for this project Table 2 Design Project Milestones Index Start Date End Date Milestones Group Status 1 Oct Ly 2000 Oct 30 2000 Initial research All members Completed 2 Nov1 2000 Nov 31 2000 Submit proposal
16. polling The function will exit after it receives the entire EOS from the COM port of the PC Since a cable is used as the transmission channel the error in the channel is assumed to be zero That is the EOS will arrive to the receiver with no error As stated in the interim report the intended method to access the COM2 of the Motorola Board was to use the Serial Management Controller SMC But in this implementation the serial output port has been switched to COM 1 which is the console port of the Motorola Board Since COM1 of the Motorola Board is used the maximum achievable transmission speed is 9600 baud Accesses to the console port of the Motorola Board are done by directly controlling the ISA bus where the COM1 is connected This unique method is necessary since the CPM is not initialized and the only way to get access to communication port is by direct access to the data bus that it is connected A single buffer pool is used for either transmit or receive is due to the fact that it is adequate and sufficient for a polling receive algorithm For example when the Copy Module decided to go into recetve mode by waiting for incoming serial data it blocks until the entire packet with the EOS Before the Copy Module perform any further receiving of serial data it will call the assemble function to transfer the incoming serial data to a ready to send Ethernet transmit packet After that the Copy Module will set the empty flag for the seri
17. polling algorithm that has been proven working The polling algorithm limits the performance of the system due to its block recetve behaviour The performance of the system would be increased if the interrupt driven implementation is used In the Motorola Board there are two COM ports available to use COMI is used because it was discovered that that COM2 does not have a transceiver suitable for a RS 232 interface Also a better understanding of the functionality of the COM1 in the Motorola Board since it is proven working by the debug program for the board can make using COM1 an easier task However it is known that when using the console port for data transmission connection to the only debug terminal has been lost This will make the process of debugging the code a lot harder later on Nevertheless it was still decided to use COM1 because it seems to have a better chance of success using a working COM port instead of trying to work with a COM port that no documentations are available Careful measures were taken to ensure the data is correct before preceded to remove the terminal that connects to the COM 1 port For the actual verification and testing please refer to section Testing and Verification for Constructed Prototype in this report Also for the serial interface the method to directly access the ISA bus that connects to the COM 1 port of the Motorola board was chosen instead of the SMC implementation The SMC implementation i
18. segment in the packet for serial transmission Also a serial TX BD will be pointed to the End of Packet Sequence after the Ethernet buffer is fully disassembled The disassemble function will set the Ready Bit of the serial TX BDs associated with the Ethernet packet to 1 for CPM processing Disassemble function decrements disassemble status variable to indicate the data packet stored in the buffer has been disassembled Move Current_Unprocessed_Ethernet_RX_Ptr to the next BD in the Ethernet RX BD table CPM is constantly monitoring the empty bits of the serial Transmit BD when it finds BDs that have ready bits set to 1 it processes the buffer by copying the data in the buffer to the serial Transmit FIFO queue After the BD is processed the ready bit of the BD is set to 0 The serial interface hardware sends out data in the serial Transmit FIFO queue After CPM processes a serial TX BD that is pointed to the End of Sequence it generates a serial interrupt to trigger serial Transmit ISR 11 The ISR will acknowledge the Ethernet Cleanup routine 12 The Ethernet Cleanup routine will free up the buffer that holds the sent packet D 2 4 TRANSMISSION OF DATA FROM SERIAL TO ETHERNET INTERFACE Figure D 5 shows the different interactions of these components when a data packet comes in from the serial interface System Ethernet_Serial_System from Serial to Ethernet Initialize lt Pa Ethernet Interf
19. sini oaunnaa ana D 17 D32 System Intalizatot rocs erirereiinuneneanai ieia D 19 D33 Module Descriptions ini mesna o cS aetievionude D 21 D 32 1 Local data Variables misisse D 21 D 3 3 2 Module Pseudocode D 21 Appendir Be Ven Manor Pim itemise naina a i ia E 1 ET Pertormariceimedsttenients anid ra aea A e E T E 1 vi E2 F n tonality WSS Us ssa giesaciesnsnavncavantnussavneneoetaaepaavinayneaying a saai E 1 E21 Bihena ODE ca usisteresisteatreascastoeshspuaeanchiasesindabnatiaieastteabantiaesisluarnadin E 1 E22 Serial modile iisas aan S A S E 2 E23 Assemble midtlesiiiriciaioonicosiani naiai E 2 B24 Drsasseniblemodilisiraasanna iksi E 2 E23 Copy modileremeeneaa ennn n E 2 Appendix F Test plan for the constructed design prototype sssesssessserisseieseese F 1 F 1 Preliminary Verification Datasheet esssssesssessessessrssessrssersressrsereerresee F 3 Appendix G Verification PLan for the Paper Design ss ssssesssesssesreserrsrresrreseresee G 1 Gl ATVI naraenia E eai EST Eaa RENAE OS eR G 1 G 2 Ethernet and Serial Interface Delays s sssssesseeseessessessesrsseesressrsreereesee G 2 G 3 Communications Processor Module CPM Utilization 0 G 3 G4 Software DelaySrssisnini snidani seansa a a aR Aaa AE G 5 Go Oe Us banaane eee eo ee a ee eee G 5 Appendix H prototype test measurement data cwwainuaurimncnmsmnpmnauuene H 1 Appendix k Design Audit Prototype Dem sriireriiereriiitrikre niihinkin I 1 vii LIST OF FIGURES
20. test the ARP reply feature of our design Our PC will be sending valid ping packets to the Motorola board Initially we verify that the PC does not contain an entry for the IP address we are pinging Then when the PC first pings the IP address it will first sends a broadcast packet which contains an ARP request The PC s ARP table is then checked to ensure it contains an entry which associate the Motorola board s hardware address with that IP we re pinging to This procedure tests both the ARP reply feature and the Ethernet sending and recetving components E 2 2 SERIAL MODULE The unit testing of the serial module is accomplished by sending a string from the PC to the Motorola board s console interface Either using the cat Linux command or directly typing to the console port can do this The test program running on the Motorola board will call the ser_recv function and call the ser_send function to echo the characters back to the screen This procedure tests the serial sending and receiving components Our design passes this test when we use polling for the serial port COM1 but it fails when using interrupts for the serial port E 2 3 ASSEMBLE MODULE The unit testing of the copy module is accomplished by predefining some dummy buffers which simulate the buffer pools of the Ethernet and serial interfaces The dummy serial Rx buffers are filled with some pre defined patterns and the test program ensures that fragments of serial d
21. to search for the End of Sequence in the Serial buffer remove it and copy it over to the Ethernet buffer if an Ethernet packet spans across more than one Serial buffer then the Assemble function ensures the correct data and length of the Ethernet packet After the whole packet has been copied to the Ethernet side it will call the function ser_setRxBufferEmpty to notify the Serial Module that the Serial Buffer has been processed 25 C Stari D Vv Set Start End O Search for end of packet sequence record the end position of the packet Vv Add Previous_Length to Length Vv Copy data from Serial to Etherne ound end of packe sequence Yes eth_send Length eth_setEthBuffEmpty 2 en Figure 5 Flow Chart for Assemble Function 3 1 4 SYSTEM INITIATION During startup of the WELA system a script will be run to initialize the system First it will initialize the stack pointer and the interrupt vector table After which the Ethernet Initialization sequence and Serial Initialization sequence will be ran Lastly the pointers used by the Copy Module will be initialized the Rx interrupts will be enabled and finally the GetLocalIP procedure will be executed before returning to the main routine 26 3 1 5 ETHERNET INTERFACE The Ethernet Interface module contains of four API functions and one in
22. to the system s main memory using DMA transfer The CPM allows newly received port data to be copied to the system s main memory without interrupting the CPU Because of that by the time the software detects that new data has arrived the new data is already sitting in the main memory On the other hand when transmitting data to the port the CPM is responsible for copying the data from the main memory to the port s output FIFO A significant portion of the software design has to do with interfacing with the CPM hardware efficiently D 2 HIGH LEVEL DESIGN D 2 1 DESIGN APPROACH The WELA system contains four main modules Copy Module Ethernet Interface Serial Interface and Initialization Therefore a modular design approach is used Figure D 2 provides a top level structure illustration of the system Initialization initialize Ethernet_Interface Serial_Interface Control Control Flags Flags Copy_Block agpi Packet from P CPM CPM amp data from Transceiver Read Read Write Write Ethernet Packet Serial Data Buffer Buffer Figure D 2 Top Level Structure Diagram The Copy Module is subdivided into modules and the modules will be further divided into functions and procedures These are illustrated in the process structure charts in the following sections In designing the modules a top down approach is chosen It
23. transceiver Improving the error rate and implementing handshaking algorithms between transceivers Assemble serial packets into bigger Ethernet packet B 2 B 2 PROJECT MILESTONES Table B 2 Design Project Milestones Index Start Date End Date Milestones Group Status 1 Oct 1 2000 Oct 30 2000 Initial research All members Completed 2 Nov1 2000 Nov 31 2000 Submit proposal and budget All members Completed find sponsors 3 Dec 1 2000 End of Dec Develop initial system design Al members Completed 2999 finalize requirements and specifications 4 Beginning of End of Jan Decide on which FPGA and All members Decided to use Jan 2o01 ee transceiver to use Motorola board 5 Middle of Jan End of Jan Develop handshaking All members No longer part 2001 2001 i a algorithm to avoid collisions of the t on wireless channel AEA requirement 6 Middle of Jan End of Jan Investigate possible All members No longer in 2001 aN encryption schemes ase aa requirement 7 Beginning of End of Feb Develop algorithm for All members No longer in Feb 2001 2001 ee J geen o9 rettieving sending contents CUStOMEr a requirement between wireless transceiver and FPGA 8 Beginning of End of Feb Finalize design and order All members Feb 2001 2001 i 8 Ordered required components Motorola board and some sample National chips transceiver not received yet 9 May 01 2001 May 5 2001 Rev
24. 0 Buffer Struct f rsosoresosnincennaniaasanannnre nnna aat D 16 viii LIST OF TABLES Table 1 Definitions and acronyms in Design Specification Document iii Table 2 Design Project Milestones essesssssssssesseesseesseesseesstessresstessteerenereneeuntesnntesnresnresnreseeeseeeseee 13 Table 3 Mod le destiiptonssuinneninn iania naaa A A a as 16 Table 4 Description of Local Variables used in Copy Module s ssssssssesssessssersssreesrresersseesseesseee 28 Table 5 Description of Local Variables used in Assemble Function s sssesssessssresrrrssreeseesseessees 29 Table 6 Descriptions of Local Variables used in ser_send Function 32 Table 7 Description of Local Variables used in ser_tecv Function s ssssesssssssssrrssreeseeseeeseeesees 32 Table 8 Description of Local Variables used in replyARP Function essences 33 Table 9 Functional Test and Verification Restilis wanxinnsdaan sind aamineat raat neediaaen 34 Table B 1 Summary of Work Distribution s sessessssssessessessessesssessteserssrsstestertesteseestessesessresresees B 1 Table B 2 Design Project Milestones ij siciistelicuitiaiaateliensiesvednteiiee tani aalataaueiarabatenusvaaconnedaes B 3 Table B 3 Expected or Known Requirements of the Project cccseeseesseseeeesesseseeteeeeneens B 5 Table C 1 Function Specifications of the W ELA tscissassciateeriierersistarseieanvasestadasessieseveniis C 3 Table D Module TDeSei pti Otvccsssntncursaticidictnivduwtracsusat uti atersobuct
25. 1 Obtain transceivers from Wireless Decided to school lab Transceiver order our own 13 May 7 2001 May 11 2001 Revise project milestones due All members Completed week 3 14 May 14 2001 May 18 2001 Write Functional All members Completed specification Verification Plan and Test Plan due week 4 15 May 21 2001 May 31 2001 Investigate test and verify Wireless 50 wireless cominunicatiot Transceiver Completed between transceivers 16 May 21 2001 June 8 2001 Investigate how to retrieve Embedded Completed contents received from PowerPC Ethernet port on Motorola ee E board and write algorithm to module retrieve the content 17 May 21 2001 May 27 2001 Develop PC application to Embedded Completed send receive packets between PN PC and Ethernet controller Ethernet Verify packet contents mod le 18 May 21 2001 May 27 2001 Write Design Specification All members Completed and project interim report due week 5 19 May 28 2001 June 1 2001 Investigate how to access Embedded Decided to use COM2 of the Motorola board PowerPC COM 1 in order to read write to the Somat CORI transceiver ae n oqule 20 May 24 2001 June 1 2001 Request for the gad Motorola Embedded Completed MBX Evaluation Board PowerPC Software Ethernet module 21 May 28 2001 June 1 2001 Order and receive a new Wireless Completed transceiver from RF Digital 22 May 28 2001 June 8 2001 Implement and test algorithm PC utility To do for reading and s
26. EDURE This feature is not implemented yet at this point in time 27 3 2 LOW LEVEL DESIGN Table 4 Description of Local Variables used in Copy Module Variable Name Description int RxPtrFound Indicate if a free Ethernet Buffer is found int FoundARP Indicate if the entry in Ethernet Buffer is ARP Char Eth_Tx_Ptr Pointer to the current Ethernet Tx Buffer char Eth_ Rx Ptr Pointer to the current Ethernet Rx Buffer int Eth_Rx_Len Length of the currently pointed to Ethernet Rx Buffer Char Serial_Tx_Ptr Pointer to the current Serial Tx Buffer Char Serial_Rx_Ptr Pointer to the current Serial Rx Buffer Int End_Of_Sequence_Found End of sequence found for the current packet Int Previous_Length Length of Ethernet Packet split into two Serial Buffers 3 2 1 COPY MODULE Module Main eth_int loop until Eth_Tx_Ptr eth_getTxBuf NULL loop forever if RxPtrFound Check to see if there is an Ethernet Packet waiting for disassemble if Eth_Rx_Ptr eth_recv amp Eth_Rx_Len NULL RxPtrFound TRUE Search the current Ethernet Rx packet to see if it is an ARP message or not ARP_Init amp FoundARP Eth_Rx_Ptr if FoundARP TRUE Check for a Free Serial Tx Buffer so that the Ethernet Packet can be copied over Serial_Tx_Ptr ser_getTxBuf if Serial_Tx_Ptr NULL call Disassemble function RxPtrFound FALSE else 28
27. Ethernet_RX_BD_Cleanup Run After interrupt from Serial Transmit ISR First_Disassembled_Unsent_Ethernet_RX_BD_Ptr Empty 1 First_Disassembled_Unsent_Ethernet_RX_BD Ptr Size _of_BD Function Serial_RX_BD_Cleanup Function Serial_RX_BD_Cleanup Run after unterrupt from Ethernet Transmit ISR while ptr lt gt End_Of_Packet First_Assembled_Unsent_Serial_RX_BD_Ptr Empty 1 First_Assembled_Unsent_Serial_Rx_BD Ptr 8 Module Serial_Receive_ISR_Block Module Serial _Receive_ISR_Block Run After received a buffer from transceiver Save registers Unassemblett Pop registers Module Serial_Transmit_ISR_ Block Module Serial_Transmit_ISR_Block Run After received a buffer from transceiver Save registers Call EthernetRxBD cleanup Pop registers Module Ethernet_Receive_ISR_ Block Module Ethernet_Receive_ISR_Block Run After received a buffer from PC Save registers D 25 Disassemblett Pop registers Module Ethernet_Transmit_ISR_ Block Module Ethernet_Transmit_ISR_Block Run After send a buffer to PC Save registers Call SerialRxBD cleanup Pop registers D 26 APPENDIX E VERIFICATION PLAN E 1 PERFORMANCE MEASUREMENTS Due to the unexpected delays in getting the various parts of the CPM controller timer working we are unable to use the Motorola board s internal timers to record the time between
28. IFICATIONS AND JUSTIFICATIONS 2 2 3 1 BDS MODIFIED IN ETHERNET MODULE INSTEAD OF COPY MODULE In the original design the Ethernet Tx and Rx BDs are assumed to be directly accessible in the Copy Module s Assemble and Disassemble routines With clear understanding of the CPM it turns out that there are some special procedures that must be followed before gaining access to the BDs Therefore instead of modifying the BDs directly in the Copy module the BDs have been made internal of the Ethernet module The eth_send and eth_recv API functions have been implemented and perform the special procedures inside these functions This maintains the software design s modularity and allows for easier debugging 2 2 3 2 GENERATING ARP REPLY An ARP reply module was not included in the original design for Ethernet module but this turns out to be a very important feature in order to support 100 compatibility If the prototype does not reply to ARP messages the host PC will not associate remote PC s IP with the Motorola board s Ethernet hardware address Therefore the local PC will not send outgoing packets with the Motorola board s hardware address and the Motorola board will not accept the packets Therefore a generate ARP reply function was added to the Ethernet module in order to achieve Ethernet compatibility 2 3 COPY MODULE 2 3 1 MILESTONES ACHIEVED Assemble was successfully called when serial data is received from the ser
29. The conceptual representation of the design of the WELA is shown in Figure C 1 Ba aa Wireless Link ee Computer A Computer B Figure C 1 Overall System Architecture The ideal transmission rate of the adapter should be as closed to the normal Ethernet speed 10Mbps as possible Therefore the software running on the device must be able to receive packet and sending it to the remote PC with a delay of less than 1 10Mbps which translates to 0 1p1s bit However due to the limitation of budget a transceiver with a transmission rate of 50kbps is used and thus the adapter provides a maximum transmission rate of 50kbps In addition the serial port of the Motorola board is used to connect to the transceiver thus also limit the transmission rate Other faster interfaces such as the parallel port or the PCMCIA slot could have been used instead however in order to use these interfaces to improve the speed to 10Mbps additional interfacing circuitry is required Since the transceiver can support only up to 50kbps it is decided that using the serial port of the Motorola board is sufficient and logical to prove the concept By using a higher transmission rate transceiver and the parallel port of the Motorola board the adapter transmission rate can be increased to approach the speed of 1Mbps if the software code is capable of processing at such high speed Since the transceivers are much slower than the Ethernet
30. UNIVERSITY OF WATERLOO Faculty of Engineering E amp CE FOURTH YEAR DESIGN PROJECT DESIGN SIGN OFF AUDIT REPORT 4 year project group 2002 018 Wireless Ethernet LAN Adapter This report is submitted as the design sign off audit report requirement for the E amp CE 492A course It has been written solely by us and has not been submitted for academic credit before at this or any other academic institution by Henry Lai 97135281 E Kong Tse 97181644 Tim Woo 97226212 Ricky Yuen 97133950 Faculty Consultant Prof W M Loucks July 20 2001 ACKNOWLEDGEMENTS We would like to acknowledge Professor Wayne M Loucks for being our project consultant His valuable advices have helped us get through difficult obstacles that we encountered during our project development Also we would like to thank Professor Catherine H Gebotys for connecting us with Motorola Inc The heart of our project is a MBX860 Evaluation Board that is loaned from the Computer Group of the Motorola Inc Further we would like to acknowledge William Ott for lending us lab equipment to get the project started We would also like to acknowledge Roger Sanderson to whom we perform our demonstration to Then we would like to thank Tony Tam Engineering Manager of Motorola Canada for his kindness in lending us a second MBX860 Evaluation Board We also want to thank Steven Chan Technician and Neil Smith Sales Manager for their free consulting by email that gui
31. Zero 4 After data has been loaded into the Ethernet Tx Buffer set the Ethernet s Ready bit to 1 With the modified design the above responsibilities are no longer performed by the Assemble function Instead the Copy Module calls functions provided by the Ethernet and Serial Modules that actually perform the above tasks In addition the original design uses redirection of Ethernet Tx pointers to point to the Serial Rx pointers while the new design performs actual copying of data from one buffer to another instead of using pointers The main goal of these modifications is to keep the three modules as modularized as possible With the realization that the CPM must be gracefully stopped when the Status and Control bits of the BDs are to be changed the responsible of modifying those bits and checking those bits to allocate resources must be shifted to the Ethernet and Serial modules as accordingly For the Assemble function this means it must relinquish the responsibility of checking the availability of the Ethernet Tx Buffers and the presence of Serial packets in the Serial Buffer The advantage of shifting these responsibilities to the Copy Module is that when either Ethernet or Serial resource is not available the Assemble function will not be performed The new structure prevents the unnecessary idle time during looping inside the Assemble function and can move onto the Disassemble function When Assemble function is called it is ensured th
32. a runtime error occurs If any debug messages occur the debug message s text will be treated as data embedded in the received serial data This 36 will upset the operation of the program since the buffers will contain the debug message embedded with the actual data In the final implementation of the project COM2 should be used to transmit data instead of COM1 3 The current implementation fails the stress test where many collisions occur Therefore the design must be improved to better handle error conditions in transmission and receptions 4 The data are shifted by 4 bits when sending using transceiver This may be due to the problem that there is 1 byte preamble before transmission More time is needed to resolve this issue 5 The transceiver pair received from the vendor only support simplex transmission To support duplex operations additional circuitry is required This was not mentioned in the transceiver website when purchased was made and thus the required additional time was not allocated for building the extra circuitry 6 The GetLocalIP feature is not implemented yet This is necessary in order for the module to dynamically change its own IP address when plugging into different machines The IP address is currently hard coded and fixed at compile time 7 100 TCP IP compatibility is not achieved yet since Netscape will stop working when the network cable is removed and the prototype has been attached T
33. able is greater than zero it immediately returns to copy module Copy module calls eth_recv again eth_recv detects the BD is not empty so it returns a pointer to the contents of the Rx buffer and increment it s RxBD index to point to the next BD which is the buffer that CPM will use when the next packet arrives Copy module received the pointer to the Ethernet Rx buffer containing the new packet It calls the disassemble function The disassemble function copies the binary data to the serial Tx buffer append end of sequence pattern and calls ser_send ser_send converts binary data to ASCII data decrements disassemble status variable to indicate the data packet stored in the buffer has been disassembled ser_send sends data to serial port until the whole packet ser_send sets Tx buffer flag to be empty so that the Tx buffer can be re used by next call Ser_send returns disassemble calls eth_setRxBufferEmpty to indicate it has finish using the current BD buffer eth_setRxBufferEmpty sets the empty bit of the RxBD disassemble calls ser_getTxBuffer again to get a pointer to the serial buffer to prepare for next transmission 19 3 1 2 TRANSMISSION OF DATA FROM SERIAL TO ETHERNET INTERFACE Figure 2 shows the different interactions of these components when a data packet comes in from the serial interface System Serial_Ethernet_System from Serial to Ethernet Initialization Initialize
34. ace Ethernet ISR Initialization Status initialize 6 4 Decrement Copy Block Assemble Ethernet Disassemble l I l I l l I Cleanup I l I l l l Serial Cleanup Ethernet Packet Buffer Initialize NS X N N 2 v Serial Interface Serial ISR Serial Data Buffer Rx_Data 1 Rx Figure D 5 Tranmission of a Packet from Serial port to Ethernet The following sequence happens to process the data packet until it is transmitted out of the Ethernet interface 1 Data packet is received into the serial receive FIFO queue 2 CPM moves the data from the FIFO queue into the serial data buffer 3 CPM generates a serial interrupt to trigger serial Receive ISR The ISR increments the assemble status variable to indicate that there is one more packet ready for assemble 4 The copy module is constantly checking for the assemble status variable 5 When the status variable indicates that there is an unprocessed data the assemble function will attempt to locate the unprocessed data buffers are process based on a FIFO scheme This is done by checking the BD that is pointed by the Current_Unprocessed_Serial_RX_Ptr of the Serial RX BD table The assemble function reads in the data length and the starting location of the data 6 The As
35. aes teat aain D 5 Table D 2 Description of Global V atiables ncciniatiutiruvaiaulitinspaie itidiearaibulidiies D 15 Table D 3 Description of Constants used during System Initialization cee D 19 Table D 4 Description of Local Variables used during Copy Module D 21 ix 1 0 INTRODUCTION This document describes the 4 year design project completion status at sign off time In the first section of this document it describes the milestones achieved and missed at sign off time It also describes the modifications made to the original design and justification for the changes In the second section of the document it presents a design audit This design audit contains the modified design specifications for the software design which shows the good software design principles that have been followed It also contains the test and verification data for the constructed prototype 2 0 MILESTONES ACHIEVED AND MISSED 2 1 REASON FOR MISSING MILESTONES One of the major obstacles encountered is the lack of detailed documentation to the Motorola board that used for the prototype design On delivery of the board there are three booklets that come with it All three of them do not contain any documentation as to how to set up the different ports on the board After performing some search on the Internet we were able to find some sample code for another Motorola board ADS860 Our board is MBX860 and the only similarity of the two boards is that
36. al receive buffer As described the buffer is used in a strictly sequential fashion and one such buffer is adequate Accordingly the same reason applies to why only one serial transmit buffer is enough The Copy Module copies all the data plus the EOS into the serial transmit buffer and call serial send function The function will send all the data out to the console port of the Motorola Board before returning After the data has been sent the serial send function will set the empty bit of the serial transmit buffer to indicate that it is free for next use It was decided upon to use polling algorithm for data access in the serial interface This is not the intended method for accessing data Actually data polling algorithm is done earlier in the project implementation phase and is used for testing in the system integration phase However problems were encountered when tried to change the polling algorithm to a fully interrupt driven implementation Documentation and procedures were followed and appropriate setups have been performed however it still failed It is suspected that the interrupt from the Ethernet source and the ISA source conflicts each other One such explanation might be due to the fact that the normal way of accessing the COM port was 10 omitted The normal way to access the COM port is through the use of serial channel provided in by the core processor Due to the time limit of the project it is decided upon to use the
37. at the main task of assembling Serial packets into Ethernet packets is performed 2 4 SERIAL INTERFACE 2 4 1 MILESTONES ACHIEVED Successful receive and transmit data through the console port COM1 of the Motorola Board was accomplished When serial data is sent through the COM port of the PC to the console port of the Motorola Board the serial interface can receive the data and transfer it to a designated buffer pool Also when data is put in the serial transmit buffer the serial send function can transmit the data to the console port of the Motorola Board All data in the serial transmit buffer is first converted into ASCII format before transmitting Therefore the display on the screen in the console port is the actual HEX data in the serial transmit buffer pool 2 4 2 MODIFICATIONS AND JUSTIFICATIONS Instead of having a chain of BDs pointing to a large buffer pool it is decided upon to use two buffer pools There is a serial transmit and a serial recetve buffer The size of either buffer is sufficient to hold an entire Ethernet packet of maximum size which is 1520 byte With single buffer pool implementation there is no need to provide a BD structure since the same buffer pool can be reused due to the polling nature of the receive function Without the BD structure there is no need to use the CPM Therefore CPM is only enabled in the Ethernet interface In the receive function it will receive the data from the serial FIFO by
38. ata Ethernet m FIFO Cleanup Rx_Data 5 Rx T Disassemble armen 18 Call 4 Waiting 15 set empty Tx Buffer Flag 2 Check Buffer Ethernet Packet Buffer Serial Data Buffer Figure 1 Transmission of a Packet from Ethernet to Serial port The following sequence is used to process the data packet until it is transmitted out of the serial interface in the modified design 1 Copy module gets a serial Tx buffer from serial module by calling ser_getTxBuffer 2 In ser_getTxBuffer if the serial Tx buffer is not in use it returns a pointer to Tx buffer and sets a flag to indicate the Tx buffer is now in use 3 Copy module calls eth_recv If no packets are ready then it quits and call ser_recv 4 In the normal flow the program will always be inside ser_recv waiting for a complete packet from serial interface until EOS is detected 5 Data packet is received into the Ethernet receive FIFO queue 6 CPM moves the data from the FIFO queue into the Ethernet receive buffer 18 10 11 12 13 14 15 16 17 18 CPM generates an Ethernet interrupt to trigger Ethernet Receive ISR The ISR increments the disassemble status variable to indicate that there is one more packet ready for disassemble The ser_recv is constantly checking for the disassemble status variable If disassemble vari
39. ata can be assembled back into a complete Ethernet packet and copied into the Ethernet Tx buffer The memory contents of the dummy Ethernet Tx buffer is then examined to verify it contains valid data E 2 4 DISASSEMBLE MODULE Disassemble can be tested in a similar way as the Assemble module Pre defined data are loaded into the Ethernet Rx buffer and the dummy serial Tx buffer contents are verified to contain correct disassembled fragments of the original Ethernet packet E 2 5 COPY MODULE The testing of the copy module is in fact the integration test of our entire software design First run the PC network monitor on the PC Then ping the Motorola board from the PC and the packet content should show up on the serial console s screen At the same time we can send pre defined packet data from the PC s serial port to the Motorola board The same packet content should appear at the PC network monitor To verify the serial data are transferred correctly we need to convert data input and output to console screen to a human readable format Our data packet received from the Ethernet port are first converted to ASCII code before it actually got sent to screen E 2 Similarly the code we downloaded to the console are in ASCII format for easier debugging APPENDIX F TEST PLAN FOR THE CONSTRUCTED DESIGN PROTOTYPE This section explains how the performance specifications can be measured To ensure 100 compatibility with existing Ethern
40. block of the Copy module Disassemble Start CopyToSer Serial_Tx_ Ptr Eth_Rx_Ptr Eth_Rx_Len ser_send Eth_Rx_Len 4 eth_setRxBufferEmpty e en C End J Figure 4 Flow Chart for Disassemble Function As shown in Figure 4 the new Disassemble block simply copy the data from the Ethernet receive buffer to the serial transmit buffer Then it will pad four byte of End Of Sequence EOS to indicate to the serial receive at the other end that the end of the Ethernet packet is reached Therefore the length passed into the function ser_send is increased by four to let the send function not only send the entire Ethernet packet but also include the EOS bytes After it finished sending the data the Disassemble function will call eth_setRxBufferEmpty to set the Empty bit of the Ethernet Receive BD Flow Chart for the Assemble Function 24 3 1 3 2 FLOW CHART FOR THE ASSEMBLE FUNCTION As shown in the following Figure 5 the Assemble function has been greatly simplified The Assemble function no longer checks which Serial Rx Buffer contains data and which Ethernet Tx Buffer is empty In addition it does not have to wait for notification from the Ethernet Module that the Ethernet packet has actually been sent to the PC and that it is now empty and can be reused The functionalities which the new Assemble function is responsible for ate
41. both use the same processor PPC860 whereas everything else differs between the two boards Of the sample code that we downloaded there is one file that contains the Ethernet port initialization steps We have tried to use those steps by executing in the same order with the values set as appropriate for the MBX860 board However this proves to be unsuccessful After which we have search on the Internet again this time we found the user manual for PPC860 the processing chip itself The PPC860 documentation contains a section on Ethernet and in it there is a 35 step initialization sequence of the Ethernet port 1 We have matched the 35 steps with the initialization sequence we got for the ADS860 board and we found some differences between the two Upon this discovery we hope that the cause of our problem lies in the differences and thus we tried to use the 35 step initialization sequence However after the modifications have been made we were still unable to perform normal communication between the PC and the Ethernet port of the Motorola board With insufficient documentation we do not see any clear path to establish communication between the Ethernet port and the PC This led us to consider the option of loading an operating system onto the MBX860 board We found two alternatives Embedded Red Hat Linux or Embedded Configurable Operating System ECOS We tried to install both of them however the installation for both OS is unsuccessfu
42. ceive functions alternately If data from the Ethernet interface is ready it will disassemble the packet into smaller serial port packet For data coming in from the serial port stored in serial buffer it will reassemble the packet into larger Ethernet port packet The Initialization block is used to set up and initialize all global data structures This part remains the same as the design specification in interim report 3 1 1 TRANSMISSION OF DATA FROM ETHERNET TO SERIAL INTERFACE The data flow from Ethernet to serial interface in the modified design is roughly the same as the one in interim report The major change is that all sending and receiving tasks are done by API calls instead of directly accessing the BDs Rather than directly checking the status flags modified by the ISR the Copy module now must obtain the current status by the return value of the API function calls The flags are kept internal inside the interface modules The following Figure 1 shows the transmission of a packet from the Ethernet port to the Serial port 17 System Ethernet_Serial_System from Ethernet to Serial A Initialization Initialize a N Initialize X Initialize Status 13 Decrement Copy Block w Serial Interface Get Serial Buffer AA Ethernet Interface Ethernet ISR ad Assemble 2 Return Ptr Serial ISR 7 ISR GPM Re 3 Receive 14 Tx_D
43. ded us in the right direction GLOSSARY OF TERMS amp ACRONYMS Table 1 contains the definitions and acronyms used in this design specification document Table 1 Definitions and acronyms in Design Specification Document Term ARP BD COM 1 CP CPM DMA ECOS EDK IP ISR OS PC RxBD SMC SCC SDMA Tx TxBD Definition Address Resolution Protocol Buffer Descriptor Console Port Communication Processor Communication Processor Module Direct Memory Access Embedded Configurable Operating System Embedded Development Kit Internet Protocol Interrupt Service Routine Operating System Personal Computer Receive Receive Buffer Descriptor Serial Management Controller Serial Communication Controller Serial DMA Transmit Transmit Buffer Descriptor iii TABLE OF CONTENTS ZEA NONW EC ENTE Sis in r aces een ba ita Sa E EE R AA ii Glossary of terms Sc Acronyms aiiinuieiandiniiiendinndaandind iiia i iii Table OF Contents manidiomnamndmonie an A a a a Angie iv list of Fig f se nena na a aA r AA E a arte at viii List OF Tables pniiudwatanpiiiaitiiarivadeaiat n a a a a ix LW sete an eid es RE E O A E E AS Introduction PA EEEE E E EEE Milestones Achieved and Missed 2 1 Reason for Missing milestones ssssesssessssressrissresseeeseeesereneesneesnresnresserse 2 2 2 Ethernet moddlesasisnesunnnzona aa an 4 221 Milestones Achieved ninisacannaaiasanedannacn a daaci iina 4 22 2 Malestones MISA cakskcvsscutuesaucu
44. dextt Find next unprocessed BD in Serial RxBD table It is guaranteed that there will be at least 1 not nk Empty entry else this function won t be called if SerialRxBD SerialRxBDindex Empty 0 Found_free_serial_RxBD true Serial Rx_Byte_Ptr SerialRxBD SerialRxBDindex Buffer_Ptr Serial Rx_Byte_Length SerialRxBD SerialRxBDindex Length until Found_free_serial_RxBD if BD is the first BD for new packet find an empty Ethernet Tx slot to store the serial data If there are not free Tx slot this will loop forever Meanwhile the CPM will keep processing data in background and update the BD Hopefully there will be an empty slot eventually y found_free_ethernet_TxDB false Repeat if Ethernet_TxBDindex Max_Ethernet_TxBD_Size Ethernet_TxBDindex 0 else Ethernet_TxBDindex If EthernetTxBD Ethernet_TxBDindex Ready 0 Found_free_ethernet_TxDB true Until found_free_ethernet_TxDB oa Current_Packet_Length 0 Ethernet Tx _Buffer_ Ptr Serial Rx_Byte_Ptr else if received data contain end of packet sequence D 22 EthernetTxBD Ethernet_TxBDindex Length Current_Packet_Length Serial Rx_Byte_Ptr Serial Rx_Byte_Length of unprocessed BD setting the ready bit will automatically cause the CPM to send the buffer in background PacketReady t EthernetT
45. e of 1 in the Empty Status Bits indicates that the BD is available for use When new data arrive from the serial port the assemble function will reassemble all the partitioned packets that the serial port has received back into an Ethernet packet After the Ethernet packet is sent to PC an ISR will notify the Serial RxBD Cleanup function to mark the Empty Status Bit of the Serial BDs that are used to reconstruct the Ethernet packet to 1 Module Copy_Block Modify Serial xBD Ready Bit Modify Ethernet TxBD Ready Bit Disassemble Assemble Ethernet Rx Serial Rx wt e SS ISR ISR odify Ethernet N Modify Serial N xBD Empty Bit xBD Empty Bit Ethernet RxBD Serial RxBD thernet erial Tx Ethernet Tx Cleanup Saale Cleanup lt sa Figure D 6 Block Diagram for Copy Module D 10 D 2 5 1 Flow Chart for the Disassemble Function Figure D 7 shows the flow chart for the disassemble function that is part of the copy module Disassemble a Start X P P Set 1st entry currentRxBD No wer a lt _EmptyBit 0 ba oe PSS a Ne Yes v Check for Space in Serial TxBD Wait for space in the Serial TxBD pr ra E No lt SS Found free space in the aiy z a Free Space Yes Give byte_Ptr amp Serial TxBD byte_length to Serial Enable Tx
46. e original cable Also when receiving a packet from the remote end the source IP address should not change so that the local PC will think that the packet comes from the remote PC directly The modules should be completely invisible to the host PCs The transmission rate of the transceiver and the processing speed of the processor on the evaluation board limit the transmission rate of the design Each constraint must be verified independently Both the evaluation board and the transceiver should be capable of operating at 10Mps in order to achieve an overall transmission rate of 10Mps for the adapter However as discussed in the functional requirement the transceiver selected for this project has a maximum transmission rate of 50kbps due to the limited budget We first need to verify that the evaluation board can operate at a rate of 10Mps regardless of the transceiver used We also have to verify that the transceiver can operate at a rate of 50kbps The way to verify that the evaluation board can operate at a rate of 10Mps is by estimating the delay between recetving a packet from PC and sending the packet to the transceiver From the user manuals the overhead of the processing instructions can be estimated It is impossible to achieve 10Mbps if there is a high delay such as busy wait in the code We can also verify the maximum rate of the port we have chosen to use by reading the relevant documentation If the port we have chosen to use has a
47. e will be attached to the Ethernet port and check for network functionality The second priority from the customer is cost The customer only provides 400 for the construction of this prototype Therefore the components of the prototype of the WELA are mostly sponsored from other companies However the cost of the final product can be reduced significantly in mass production Another critical requirement from the customer is the transmission rate which is the third priority The ideal transmission rate should be as close to normal Ethernet speed 10Mbps as possible However due to the limited budget a slower prototype is build to demonstrate the concept of the device To conserve budget it is agreed that a transceiver with a maximum transmission rate of 50kbps is used for this prototype In addition the maximum transfer rate of the serial port on the Motorola board used is 2 4Mbps The logical processing of the code used also requires additional time Upon completion of the prototype if there is an interest in the device from the customer the transmission rate can easily be improved by using faster transceiver faster processor and optimisation of codes The fourth fifth and sixth priorities from the customer are the transmission distance the packet error rate and the transceiver output power respectively The customer requires that the device can support a maximum distance of 25 meters under normal condition with a packet error rate
48. ed during initialization Table D 3 provides the description of these constants Table D 3 Description of Constants used during System Initialization Constant Description TX_BD_TABLE_PTR This is a value to indicate the starting memory location of the transmit buffer descriptor MAX TX BD_ SIZE This is a value to indicate the number of transmit buffer descriptors RX_BD_TABLE_ PTR This is a value to indicate the starting memory location of the receive buffer descriptor MAX RX BD_ SIZE This is a value to indicate the number of receive buffer descriptors for the Serial Interface The following is the system initialization code Begin System Initialization Initialization stack pointer Initialization interrupt vector table Execute Ethernet Initialization Routine Execute Serial Initialization Routine Initialize pointers used by main Copy Routine Enable Rx interrupts Execute GetLocalIP procedure End of System Initialization Ethernet Initialization Initialize the SCC to be used in Ethernet mode Initialize SDMA configuration register Initialize RxBD Initializes all BD in RxBD for i 0 to max_number_of_BD_in_RxBD_table empty bit 1 Set buffer pointers to point to the correct receive buffer currentRxBD first entry Initializes all BD in TxBD D 19 for i 0 to max_number_of_BD_in_TxBD_table ready bit 0 Set buffer
49. eless medium Transceiver Rate 50kbps Distance 25m Supply Power 12V Output Power 1mW Ethernet Network Compatibility Transmission Rate 50kbps IP Address Automatically configured to remote PC s address Error Detection Header error detection C 3 Busy Signals Automatically generate collision signals when local buffer is full C 4 APPENDIX D DESIGN SPECIFICATIONS D 1 OVERVIEW The WELA system consists of both hardware and software components Our hardware components consist of the Motorola MBX860 Evaluation board and transceivers The Motorola board has an Ethernet port and a serial port The main design of the project is to wtite efficient software code to interface between the Ethernet port and serial port A top level system diagram of the WELA system is shown in Figure D 1 ef ee Wireless Link Transceiver J ie Transceiver RS232 RS232 Wireless Wireless E Ethernet Ethernet Adapter Adapter Ss eee A B 1 MS cl Computer A Computer B Figure D 1 Top Level System Diagram All port data transfers on the Motorola board are coordinated by the Communication Processor Module CPM hardware inside the PowerPC 860 chip The CPM is responsible for copying the data received from the port s FIFO
50. ending to saitware transceiver 23 June 1 2001 June 15 2001 Test transceiver for Wireless 50 Completed functionality 14 24 June 5 2001 June 15 2001 Write programs in PC to PC utility Completed disassemble and assemble software packets 25 June 10 2001 June 20 2001 Write programs in PC to send PC utility Completed and receive data in the serial software port 26 June 10 2001 June 17 2001 Merge the different modules All members 70 of the code together Cotaplet d 27 June 17 2001 July 7 2001 Testing of the entire system All members 70 Completed 28 July 1 2001 July 7 2001 Target project completion To do date 29 July 16 2001 July 20 2001 Project signoff due week 12 All members To do 30 July 16 2001 July 22 2001 All members To do Design project abstract due week 13 15 3 0 DESIGN AUDIT 3 1 HIGH LEVEL DESIGN The overall high level design remains the same as the original design in the interim report with some minor modifications made to it Please refer to Appendix D for the original design specification In the new design the Ethernet module copy module and serial module still act as the three main components of the design To keep the modules more self contained thus making them have higher cohesion and lower coupling the number of the buffers have been limited and various flags internal to the modules only are used and o
51. esseveecees 17 3 1 2 Transmission of Data from Serial to Ethernet Interface occccscssvseecees 20 3 1 3 Block Diagram for the Copy Module ecsosssssssssssssssssssssssssssavsssssseassssees 21 3 1 3 1 Flow Chart for the Disassemble Function scssi 24 3 1 3 2 Flow Chart For The Assemble Function ossessi 25 IAA System nitat eriirecicriienceni i n E an E a 26 ISo Ethernet Inia niaii a a a ytasbomeg Sede 27 3M6 Serial Interjait sisinio ae a pia 27 DAF GetlocallP Procedure nsisiisarananraia iiaiai eE Ea 27 3 2 Low Level Desiofirnuniniia nn na aaa a a aT 28 32A Copy NOL Cac de Svan inn iia a tab Ra E E a 28 DATE Disassemble DIDI atk sces ta svsa vices a e R rN 29 Pe hve Assemble Blok asiaa n a a E 29 3 2 2 LEIDER Functions niei a ak alae eiaty 30 IZZ ARP a a eit cece ena 30 Be DD CUE ANUP sites ies E E EEE EA E 31 323a Seral FUNGONS fas east E Das sian Mss acu yok ha octet VoueU NE S 31 3 2 31 ser_setRxBuferEmpty function soxavestsviasvaeapeaveslavnsseinapeaseelavedeantiors 31 32 3 2 seret T xBuf PANN csvcrcsivieucariaiisieus aa SeaweeunaNes eee 31 323 3 ser tend Funihot wisina na a 32 324 ARP Rph Funcom esiseina pia 33 A A E S Prototype Testing and Verification Results 4 1 Plan for Improving the Not yet Perfect Areas icsicsicotutintiientuse 38 SP EEEE E EESE EEE References 16 34 39 Appendix A Customer Require Mice ts ciahscacaisieveatuaas caetansindyeaagesntavadennnenrnns A 1 Appendix B Project Plan and Mi
52. et network the following will be performed 1 Remove existing Ethernet cable on Computer A and Computer B connect the WELA to the Ethernet port on each computer Leave all networking settings unchanged Computer A pings Computer B Transfer a text file from Computer A to Computer B Connect Computer A to the Internet Computer B access the Internet using Internet connection provided by Computer A assuming Computer A has been configured as a proxy server Ore IS If items 3 to 5 do not generate any errors Ethernet network compatibility is met The verification of the transmission rate and the transmission distance can be performed together after the prototype WELA is successfully verified to be compatible with Ethernet network To ensure a transmission speed of 50kbps and a distance of 25 meters can be achieved the following will be performed 1 Move Computer A and Computer B 25 meters apart 2 Setup Ethernet connection between Computer A and Computer B using the prototypes 3 Runa program that will send a stream of data from Computer A to Computer B and Computer B sends the same information back to the Computer A The time for WELA A to send the data from Computer A to WELA B and WELA B to send the data back to WELA A will be measured Two complete transfers are in this time frame The transmission rate can be found by dividing the number of bits in the data by the time required for one transfer F 1 4 Repeat step three
53. he packet can arrives the destination successfully but there are not responses from the other computer It is suspected that there are some address fields in an IP packet require modification that is causing this problem It is strongly believed that given more time the problem areas as stated above would be fixed before the final product demonstration in January 2002 37 4 1 PLAN FOR IMPROVING THE NOT YET PERFECT AREAS A high priority should be given to make the serial transmission and reception fully interrupt driven More time is needed to investigate how to make CPM accept interrupts from the ISA bus controller The priority assignments of the CPM interrupts must also be investigated so that both Ethernet and serial interrupts can be handled correctly The current design fails the stress test where collisions occur This must be resolved before going for full scale production From the current knowledge of the CPM it is known that when CPM senses an error when receiving it will skip the current BD and proceed to next BD Therefore the current RxBD will contain the partially received packet and will never be emptied again Therefore the Ethernet ISR must be notified such that it will reset the empty bit when an error occurs It is also necessary to have the timer enabled in order to calculate the processing delay of the software code The timer must be running on the board in order to obtain accurate measurement of the speed M
54. how to access Embedded To do COM2 of the Motorola board PowerPC Software in order to read write to the serial port transceiver mod le 20 May 24 2001 June1 2001 Request for the 2 Motorola Embedded Pending MBX Evaluation Board PowerPC Software Ethernet module 21 May 28 2001 June 1 2001 Order and receive a new Wireless Completed transceiver from RF Digital 22 May 28 2001 June 8 2001 Implement and test algorithm PC utility To do for reading and sending to Sotware transceiver 23 June 1 2001 June 15 2001 Test transceiver for Wireless 50 functionality Completed 24 May 28 2001 June 8 2001 Implement and test algorithm PC utility To do for reading and sending to saitwate transceiver 25 June 5 2001 June 15 2001 Write programs in PC to PC utility To do disassemble and assemble software packets 26 June 10 2001 June 20 2001 Write programs in PC to send PC utility To do software and receive data in the serial port B 4 27 June 10 2001 June 17 2001 Merge the different modules All members To do of the code together 28 June 17 2001 July 7 2001 Testing of the entire system All members To do 29 July 1 2001 July 7 2001 Target project completion To do date 30 July 16 2001 j July 20 2001 Project signoff due week 12 All members To do 31 July 16 2001 July 22 2001 Design project abstract due All members To do week 13 B
55. ial module In addition Disassemble was successfully called when received Ethernet data from the Ethernet module 2 3 2 MILESTONES MISSED The requirements for the Copy module are satisfied at signoff time However additional testing will always yield more reliable and robust code 2 3 3 MODIFICATIONS AND JUSTIFICATIONS In the original design the Copy module simply calls Assemble and Disassemble in a round robin fashion and let the Assemble and Disassemble functions to determine whether data is available In the current design the Copy module will call the corresponding interface s API functions only when the data required by that function is available This change is made to make the design more modular Since the BDs are now kept internal to the interface modules and calling the corresponding API function will simply return a pointer to the internal buffer the Assemble and Disassemble functions now simply copy the data from one buffer to the other buffer The Copy module ensures the Assemble and Disassemble will be called only when there are valid data in the buffers i e when the API functions does not return NULL 2 3 4 DISASSEMBLE BLOCK OF THE COPY MODULE 2 3 4 1 MILESTONES ACHIEVED The coding and the testing of the Disassemble block of the Copy module are completed The function can successfully take a controlled packet from the PC and redirect it to the Console port COM 1 of the Motorola Board However
56. iated computer The D 13 associated computer broadcasts its IP through the reply message it sends to the wireless Ethernet adapter After both the wireless Ethernet adapter A and B have received the IP of their associated computer they will send each other a message to exchange this information After this exchange of information the two Ethernet adapters will then configure their own IP address to be that of the computer they are not attached to This procedure is illustrated in the following Figure D 9 3 Notify Adaptor B 1 Querying IP with Computer A IP 1 Querying IP address Wireless Ethernet Adapter B Wireless Ethernet Adapter A Computer B 3 Notify Adaptor A with Computer B IP 2 Reply with IP address 2 Reply with IP Computer A Figure D 9 GetLocalIP Procedure Diagram D 14 D 3 LOW LEVEL DESIGN D 3 1 GLOBAL STRUCTURES In the following Table D 2 the description of the global variables used for the WELA system is explained Table D 2 Description of Global Variables Variable Name int Unassemble int Disassemble int EthernetTx_Buffer_Ptr int EthernetRx_Buffer_Ptr int SerialTx_Byte_Ptr int SerialRx_Byte_Ptr int Current_Unprocessed_Serial_Rx_Ptr int Current_Unprocessed_Ethernet_Rx_Ptr int First_Disassembled_Unsent_Ethernet_RX_BD_Ptr int First_Assembled_Unsent_Serial RX BD_Ptr Description The total number of received serial buffer
57. ion between Computer A and Computer B using the prototypes 2 Runa program that will send a steam of data from Computer A to Computer B Record the power indicated on the power meter F 2 F 1 PRELIMINARY VERIFICATION DATASHEET Preliminary Verification for Max Software Speed Instruction type load store single load store multiple add mult comp branch hit branch miss Total 30 10 16 4 20 10 10 100 7 23 NOE Na cos Total delay total of Instructions Average delay instruction Max baud rate Total delay transfer of bits transfer of Instructions 20 30 40 50 60 70 100 200 Assuming 32 bit per data transfer Total delay transfer ns 5820 8730 11640 14550 17460 20370 29100 58200 F 3 5498 281787 3665 521191 2749 140893 2199 312715 1832 760596 1570 937653 1099 656357 549 8281 787 60 60 25 25 25 25 25 Maximum baud rate kbps ticks instruction period ns delay ns 126 138 4 3 5 10 5 291 APPENDIX G VERIFICATION PLAN FOR THE PAPER DESIGN G 1 OVERVIEW This section discusses how the design will be verified to satisfy all the performance specifications before the prototype is created To verify that the module is 100 compatible and fully plug and play it is necessary to ensure that the PC does not have to change the packet s destination IP address in order to use our module to send the packet instead of using th
58. is because a top down approach is suitable for group discussions and it gives a clear analysis of the functionality of the whole WELA system However in the implementation of the WELA system a bottom up approach will be used because facilitates debugging and testing of the programmed code separately Also it allows a better work division among the group members The modules should be able to be tested individually and then combined together to form the whole WELA system D 2 2 SYSTEM EVENT DIAGRAM Figure D 3 is the system event diagram which shows the logical sequence of events that happens when Computer A wants to send a packet to Computer B During a normal transmission the packet arrives the Ethernet interface of the adapter The Ethernet packet is partitioned into smaller data chunks and put into the serial transmit interface The smaller data chunk leaves the serial interface and is sent through the wireless transceiver Then the serial interface notifies the Ethernet interface that the serial interface is ready to transmit the next data chunk Adapter A keeps sending those partitioned data chunks until the entire Ethernet packet has been transmitted On the remote side when Adapter B s transceiver receives the data from adapter A s transceiver the data is first put into a local buffer by the CPM It keeps receiving packets until the entire Ethernet packet has been received Then the Ethernet interface of Adapter B checks if the heade
59. ise customer requirements All members Completed due week 2 10 April 20 2001 May 7 2001 Power up Motorola board and All members Completed verify PC can communicate with debug console 11 May 7 2001 May 14 2001 Verify PC can ping Ethernet Embedded Completed port of Motorola board and PowerPC investigate how to control the porate VEstee W Ethernet Ethernet port aodule 12 May 01 2001 May 11 2001 Obtain transceivers from Wireless Decided to school lab Transceiver order our own 13 May 7 2001 May 11 2001 Revise project milestones due All members Completed week 3 B 3 14 May 14 2001 May 18 2001 Write Functional All members Completed specification Verification Plan and Test Plan due week 4 15 May 21 2001 May 31 2001 Investigate test and verify Wireless To do wireless communication Transceiver between transceivers 16 May 21 2001 June 8 2001 Investigate how to retrieve Embedded 80 contents received from N Completed oitware Ethernet port on Motorola Ethernet board and write algorithm to module retrieve the content 17 May 21 2001 May 27 2001 Develop PC application to Embedded To do send receive packets between ao tW PC and Ethernet controller ee Ethernet Verify packet contents mod le 18 May 21 2001 May 27 2001 Write Design Specification All members Completed and project interim report due week 5 19 May 28 2001 June 1 2001 Investigate
60. l We finally found the sample code of the ECOS driver for the Ethernet port 2 There is a different set of initialization sequence from ECOS and when we modified our code to match that of ECOS we are finally able to get Ethernet transmission to work We have encountered the same if not higher level of difficulties for setting up the serial communication This is due to the fact that neither one of the two operating systems supports the Serial Port 2 which we need for the transceivers There is a similar initialisation sequence in the user manual for PPC860 but like the Ethernet initialisation sequence we were unsuccessful at initialisation the serial port Without a schematic diagram of the MBX860 board we have no idea how the different hardware components are related It is through testing the ISA before we stumbled upon the method to access the Serial Port 1 Nevertheless we are still unable to access the desired Serial Port 2 We have contacted a Motorola representative about this lack of documentation problem The cause is that the MBX860 board we are using is actually a production board which Motorola sells to its customers whom uses this board to develop products and sells to other companies As a result Motorola does not provide any sample code for initializing the ports Whereas the ADS860 board is an evaluation board which Motorola uses as well and thus the reason there are sample codes for the ADS860 board on Motorola website
61. l Variables used in ser_recv Function Variable Name Description int pktFlag int I Indicate if a packet has been found Counter Function ser_recv int len I the pool is not empty then return NULL Means that the user forgot to call setSer_RxBufferEmpty function if ser_RxBufferPoolEmpty 32 return NULL The serial receive buffer pool is empty This function will also receive the length of packet received thru len while i lt BUFFER_SIZE amp amp pktFlag FALSE while COM1 gt LSR amp LSR_DATA_READY ser_RxBufferPool i COM1 gt buf itt len i ser_RxBufferPoolEmpty FALSI return ser_RxBufferPool Gl 3 2 4 ARP REPLY FUNCTION Table 8 Description of Local Variables used in replyARP Function Variable Name Description ARPPkt requestPkt The ARP request packet received ARPPkt replyPkt The ARP reply packet generated Function replyARP const ARPPkt_t requestPkt ARPPkt_t replyPkt copy the local HW address to source field copy the original sender s HW address into the dest field set message type to ARP_REPLY copy source HW address into source field inside ARP header copy target HW address into dest field inside ARP header copy target IP address into ARP header 33 4 0 PROTOTYPE TESTING AND VERIFICATION RESULTS The testing results indicate the design can successfully transfer data from one interface to
62. lestones acincscish cushion doervdtutibnaiebensin cant B 1 B 1 Project Ie Tea ia ors sess ee staan aot tanta cusses Ben aaa a asda is B 1 B2 Project Milestone Sirnea A E E B 3 Bist Expected nown Requirements csitsditedesiecsesitaitestictysteiduatvreduehia s B 5 Appendix C Functional Specifications se ssssesesssessresssrrssreesreesresseesneeeneennresnresreesee C 1 Appendix D Design spect Caloris iaxsivy duncan sn aurien cates detainee tarnavanmegentias D 1 DT VOVE e T E T A a mimi ies NEA D 1 D2 High Level Desigieniiraniivaniraniiveninniiraniirnniaraniiaiie D 2 DZT Dison PAD PTOI coe sai tea Seabis ac EE eau Ne van Sek vegeta A eee D 2 D227 System Event Didra annnak nanne nRa a D 3 D 2 3 Transmission of Data from Ethernet to Serial Interface D 6 D 2 4 Transmission of Data from Serial to Ethernet Interface D 8 D 2 5 Block Diagram for the Copy Module ss cassvessiscesssnsipavetensensennsledisieavies D 9 D 2 5 1 Flow Chart for the Disassemble Function ossessi D 11 D 2 5 2 Flow Chart for the Assemble Function sssi D 12 D26 lt System Initahon cnra iii aii aiai i D 13 DZI SEINE Intenatiniaann race E Aa eas D 13 D28 Seral Interfata ia E R anit esi ramon eeaannated D 13 D29 AGC Predut iiinis chara BN grins D 13 B3 MEOW EV CMD CSG hes snicta nies cteatainen ncaa tania tN a D 15 DIT Global Str ct r s orarie ea Maia ses D 15 D 3 1 1 Description of Buffer Structtte sssssssssssssssiesissrssrre D 16 D312 Addilion data strinte
63. lso the Copy module should perform the checking of the incoming Ethernet data and call Disassemble Block accordingly Therefore the validation procedure in the Copy module and the accessing of the control bits for the buffer are completely transparent to the Disassemble Block itself This results in high code modularity 2 3 5 ASSEMBLE BLOCK OF THE COPY MODULE 2 3 5 1 MILESTONES ACHIEVED The coding and the testing of the Assemble block of the Copy module ate completed The function can successfully take a controlled packet from the COM 1 of the Motorola Board and redirect it to the PC However there are several modifications made since the interim report 2 3 5 2 MODIFICATIONS AND JUSTIFICATIONS In the original design the Assemble function is responsible for keeping track of the states in which the Ethernet TxBDs and Serial RxBDs are The idea behind this original design is so that the Copy Module is responsible for allocation of resources while the Ethernet and Serial modules act according to the orders from the Copy Module The responsibilities that the Assemble function of the original design has are as follows T The Assemble function keeps track of the index of the serial RxBD that is currently being processed 2 It checks which Ethernet RxBD is empty 3 Responsible for finding free Ethernet Tx buffers by looping through the Ethernet TxBDs and checking the Ready bit of each one until found one with the status of
64. n Board We have already download and installed the development kit Budget 600 We got allocated 400 for this project However due to the fact that we cannot get the transceiver from the lab technician that have previously promised us we have to use budget to buy it ourselves This results in an over budgeted situation and we are currently trying to request for addition funding to cover the extra cost Special needs None None B 6 APPENDIX C FUNCTIONAL SPECIFICATIONS To achieve 100 Ethernet compatibility the Wireless Ethernet LAN Adapter will have a RJ45 jack that plugs into the RJ45 port of the Ethernet card This will be a seamless process that requires only plugging the device into the Ethernet port and the network will function properly The Motorola MBX860 Evaluation Board has been chosen for the demonstration of our concept For complete transparency to the host PCs in transport layer and above each local board must be able to act like the remote PC as if the PCs are directly connected to each other Therefore each local board must be set to have the remote PC s IP address to trick the local PC that it is directly connected to the remote PC This IP configuration must be done before the board can start transmitting real packets from PCs The device must also be able to discard or ask host to retransmit the packet when an invalid address checksum error is received from the host PC
65. n upper bound rate that is lower than 10Mbps then there is no way we can achieve the desired 10Mbps There are two major delays in the system The first delay is the delay in copying from the interfaces to the system main memory The Communication Processor Module CPM hardware utilization also needs to be verified to be less than 100 to make sure that the CPM has enough time to handle incoming data coming from the different ports The second delay is the delay introduced by the software running in the processor s core G 2 ETHERNET AND SERIAL INTERFACE DELAYS The CPM is a single shared resource used by all of the serial channels including the Ethernet and Serial interface It handles low level protocol processing tasks and manages DMA for all of them Managing DMA for the Ethernet interface is a significant portion of the CPM processing The worst case scenario transfer rates are given for each port from the user manual The maximum bit rate states the fastest rate that the Motorola board claims that it can transfer data for each port in the worst case G 3 COMMUNICATIONS PROCESSOR MODULE CPM UTILIZATION The Ethernet and serial interface delays gives the maximum transfer rate for each port assuming all other ports are idle However when the CPM module itself needs to serve multiple ports concurrently the CPM will not be able to process data at the port s maximum speed even if each port is capable of a faster tra
66. nction will reassemble all the partitioned packets that the serial port has received back into an Ethernet packet The Search function searches for the EOS pattern to indicate the end of an Ethernet packet One serial receive may contain more than one Ethernet packet fragments The Search function is used to distinguish between the last fragment of the current Ethernet packet and the first fragment of the next Ethernet packet After the Ethernet packet is sent to PC the Copy module will call ser_setRxBufferEmpty to indicate to serial module that the current Rx buffer can be re used for next reception of serial data 22 Start Free Space in Yes thernet pack waiting for disassemble Yes No Yes remove this packet from Ethernet Rx Buffer by calling eth_setRxBufferEmpty Is it ARP No No f y packet Check for Free Serial Tx Buffers ree Serial Buffer Yes X No Disassemble gt erial R A packet waiting Yes Yy twoByteToHex tempbuf Eth_Rx_Length thernet Tx Buff No Available Yes h A Assemble l remove this packet from Serial Rx Buffer by calling ser_setRxBufferEmpty Figure 3 Flow Chart for Copy Module 23 3 1 3 1 FLOW CHART FOR THE DISASSEMBLE FUNCTION Figure 4 is the flow chart of the working Disassemble
67. nsfer rate Therefore the maximum speed an interface can operate at is also dependent on the CPM s data processing speed CPM utilization represents the amount of time that the CPM is busy It is an analysis of whether the CPM hardware is able to transfer data at the specified rates If the CPM utilization is over 100 that means that even the software running inside core introduces zero delays in the data path the stated transfer rate is still not possible since the hardware simply cannot transfer data from the port to the memory using DMA at such high speed In the following formula the Ethernet transfer rate is the desired bit transfer rate which is 10Mbps as stated in the customer requirement The serial transfer rate is the transceiver baud rate which is 50kbps The maximum Ethernet and serial rates are the maximum rate at which the CPM can transfer data between the port and the main memory via DMA transfers Therefore the utilization of each port is given by the actual bit rate of the port divided by the theoretical maximum rate and the total CPM usage is given by the sum of the utilization of each port In our case only the Ethernet and the serial port are used The maximum rates are constants that are defined in the MPC860 user manuals Serial Rate N CPM utilization aT 2 Maximum Serial Rate Ethernet Rate Serial Rate Maximum Ethernet Rate Maximum Serial Rate If the CPM utilization is higher than 100 that means that the
68. o boatd s serial port together All except transceivers Connect one board s Ethernet port to PC A one board Ethernet port to PCB Download our program to the two boards via console port Run program on the two boards unplug from PC and connect the two board s serial port together using NULL modem Run network monitor program on PCB Ping from PC A Packet monitor program on PC B should show PC A s ping packet Pass Ethernet Stress test Ethernet receive serial transmit Run program on board Run network monitor program on PC Ping board from PC continuously Packet data should display on console continuously Pass Ethernet Stress test Ethernet receive serial transmit d Dora Run program on board Run network monitor program on PC Ping board from PC continuously Packet data should display on console continuously Pass Stress test All except transceivers ae Run program on board Run network monitor program on PC Ping board from PC At the same time send ASCII packets to board Ping packet s content should show on console while ASCII packets should show on network monitor program Fail On examining the BD s content it was shown that there are numerous collisions occurring 35 Transceiver Transceiver 1 Connect transceiver A to PC A s Fail unit test communication console
69. of less than 2 The customer stated that normal condition is one in which there ate no obstacles between the two devices As discussed with the customer the transmission distance and the packet error rate can be improved by selecting faster transceiver that will have a stronger signal For the transceiver output power the customer requires the RF output power of the transceiver to be less than ImW A longer transmission distance can be achieved if the maximum output power requirement is relaxed A 1W output power is limited due to regulations from Industry Canada The last priority is scalability The customer requires that the WELA can support a Class C Ethernet network Due to limitation of budget it is agreed that a point to point prototype is built for proof of concept To accommodate more network nodes we advised the customer that a separate collision algorithm has to be implemented Table A 1 Summary of Customer Requirements Priority Requirement Measurable 1 Compatibility with 100 compatible no reconfiguration at terminals existing Ethernet network required 2 Cost Mostly sponsored 3 Speed baud rate 50kbps 4 Distance 25m 5 Packet Error Rate 2 6 Maximum transceiver ImW output power 7 Scalability Point to point A 2 APPENDIX B PROJECT PLAN AND MILESTONES B 1 PROJECT PLAN Work distribution This project will be subdivided into several functional groups Each gr
70. om the serial port Tim and E Kong will be responsible for writing these Win32 based software Mastering Windows socket functions Develop algorithm to calculating the speed of transmission accurately Develop software to assemble and disassemble packets for display and transmission Embedded PowerPC software group Ethernet module This group will be responsible for getting Jamiliar with the use of the Ethernet port on the Motorola board Writing software code to access packets with the Ethernet port and a buffer residing on the Motorola board Main tasks include ensuring the PC and the board can communicate to each other and write code to read and write packets from the Ethernet port Tim and Henty will be responsible for writing the code for this component Minimizing the delay between receiving a packet and sending to the other interface Partitioning packets into smaller size for serial transmission Embedded PowerPC software group Serial port module This group will be responsible for getting familiar with the use of the serial port on the Motorola board and write software code to access the serial port The serial port is the port to be connected to the data pins of the transceiver Main task including writing code to read and write to the transceiver Ricky and Henry will be responsible for this part of the project Minimizing the delay between reader a buffer and send to
71. ore time is needed to enable the system timer on the Motorola so that it trigger an interrupt every certain second A counter will be incremented each time the ISR is triggered By reading the counter value change the delay can be calculated from receiving a packet to sending to the other interface Finally the GetLocallP procedure needs to be implemented so that it automatically updates the local board s IP address This can be done by pinging the local PC and retrieve the IP address of the local PC from the reply message More research on IP protocol is needed 38 ER a N 5 0 REFERENCES Motorola Inc MPC8260 PowerQUICC II User s Manual Motorola Inc 1999 Red Hat Inc ECOS CVS http sources redhat com ecos current July 09 1999 Linx Technologies HP Series II Receiver Module Design Guide Linx Technologies 2000 39 APPENDIX A CUSTOMER REQUIREMENTS The design of the WELA is fully based on the Customer Requirements It is agreed with the customer of the WELA that it is to be 100 compatible with the existing Ethernet technology IEEE 802 3 This is the first priority according to the customer This requirement is especially important as it allows users to turn an existing configured wired Ethernet network to a wireless Ethernet network without any additional capital spending expect for this device To verify that the device is 100 compatible with Ethernet standard the prototyp
72. oup member will be responsible for working on his own area Table B 1 Summary of Work Distribution Group Name Description of Responsibilities Expected Design Challenges Wireless This group will be responsible for ensuring Interface the transceiver 3 H j 7 cate H z g transceiver group he pair of transceivers can communicate to with the RS 232 port each other and meets all RF requirements Making sure that the voltage Tasks include choosing a proper antenna logic level is the same for and suitable ground piate testing the wireless ihe Motorola Beard andthe communication between the transceivers and traiieeeiver measuring the output power Ensure transceivers can operate in full duplex mode if not handshaking algorithms needed for half duplex operations Ricky and E Kong will be responsible for this component of the project PC utility software group This group will be responsible for writing all the test programs on the PC side in order to test sending and receiving packets to the Ethernet port These programs can be used not only to test the functionality of the prototype but also for obtaining different statistics about the performance of our prototype It can also provide useful information when debugging our embedded code running on the Motorola board The group also needs to write programs to send pre build packets to the serial port and to receive and display packet received fr
73. pointers to point to the correct transmit buffer currentTxBD first entry Initialize various Ethernet registers Set port to receive all packets regardless of the address promiscuous mode Set port s RxBD pointer to point to first entry in RxBD table Set port s TxBD pointer to point to first entry in TxBD table Initialize Ethernet s maximum frame size register Clear any pending Ethernet events Serial Initialization Enable the SCC for UART mode Configure transmit clock rate parity and stop bit Initialize DMA configure register Create list of RxBD and TxBD Initializes all RxBD in RxBD_List for I 0 to max_number_RxBD_in_RxBD_ List empty bit 1 buffer size 16 bytes buffer pointer buffer location Mark the last RxBD in the list Initialize RBASE register to point to first RxBD Initialize currentRxBD RBASE Initializes all TxBD in TxBD_List for I 0 to max_number_TxBD_in_TxBD_ List ready bit 0 buffer size 16 bytes buffer pointer buffer location Mark the last TxBD in the list Initialize TBASE register to point to first TxBD Initialize currentTxBD TBASE Clear all previous event in the SCCE2 event register After Initialization get localhost IP Procedure GetLocalIP begin D 20 end Send a broadcast packet Wait for localhost to reply until timeout Retrieve localhost
74. port there is a possibility that the Ethernet buffer of the board will be full The board must be able to stop receiving new packets from PC when the local Ethernet buffer is full in order to avoid overwriting any un C 2 transmitted useful data Also the device should be able to split a large Ethernet packet into smaller packets for serial transceiver transmission The WELA requires a supply power of 12V and the output power limit is set to 1mW The adapter supports a packet error rate of less than 2 The low output power requirement of the adapter as well as the required packet error rate limits the transmission distance to a maximum of 25m If a greater output power limit is permitted then the distance can be increased In addition the adapter will support a point to point network instead of a small network due to the limitation of the budget Table C 1 Function Specifications of the WELA Processor Microprocessor MPC860EN Clock Frequency 50MHz Performance 52 62 MIPS estimated Power Requirements board only Supply Power 3V 5V 12V Total Consumption 17 watts typical 5V 5 2 6 amps typical 3 3V 10 1 0 amps typical Environmental Operating Non Operating Temperature 0 C to 70 C 40 C to 85 C Humidity 10 to 80 10 to 90 Vibration 2 Gs RMS 6 Gs RMS 20 2000 Heranda A Oe Mindon Input Output Potts RJ45 Ethernet input Wir
75. r of the received Ethernet packet is valid If it is valid the packet is sent to Computer B and this means the transmission is done In the event that the Ethernet buffer is full when computer A tries to send a packet to Ethernet adapter the Ethernet interface will send a busy signal to Computer A Computer A will then retry after a certain timeout In the event that the local serial buffer is full the Ethernet interface will wait until the serial buffer is ready again Note that even if the serial buffer is full the Ethernet interface can still accept packets from local computer until the Ethernet buffer is full The computer will be notified when the Ethernet buffer can accept packets again and the normal sequence will once again be executed Ethernet Serial Computer A Interface A Interface A Sends a packet Normal Breakup packet and sent Transmission to serial interface Notify Ethernet Inferface that data is sent and ready for next data transfer Ethernet Interface Busy Receive Buffer Full Serial Interface Busy Serial FIFO Figure D 3 System Event Diagram Data send through wireless link Repeat until end of packet Serial Ethernet Interface B Interface B Link serial data into packet Computer B Forward packet if no errors detected in header Table D 1 provides a description for each of the modules of the system Table D 1
76. receiving the first piece data from one interface and the time just before the same piece of data leave the other interface For now we can only assure that our device can at least transmit and receive at 9600bps because we are able to send and receive at such rate through the serial port without any problems We can also assure that our software code can support fully duplex operations of the Ethernet and serial interfaces If we had more time we should be able to trigger the CPM timer to work correctly by setting the correct bits and enable the corresponding interrupts When Ethernet ISR is triggered because of a receive interrupt the timer is enabled Then when the data is just about to be sent to serial port by either setting the TxReady bit in polling mode or TxReady bit in BD if using CPM we can record the time and calculate the time elapsed This will give a more accurate measurement of the pure delay incurred due to the processing delay of out software code E 2 FUNCTIONALITY TESTS E 2 1 ETHERNET MODULE The unit testing of the Ethernet module is accomplished by writing a PC packet monitor program that monitor all traffic on the PC Ethernet interface The monitor program puts the PC s Ethernet interface into promiscuous mode so that any valid packets that appears on the Ethernet signal will be printed on screen The outgoing packets from PC and incoming packets to PC are printed on screen The raw data content is verified To
77. rial_TxBDindex Tx_Byte_Ptr Ethernet Rx_Buffer_Ptr While Current_Tx_Byte_Length gt 0 if Current_Tx_Byte_Length gt Max_Serial_BD_Data_Length SerialTxBD Serial_TxBDindex Tx_Byte_Length Max_Serial_BD_Data_Length Current_Tx_Byte_Length Max_Serial_BD_Data_Length Ethernet Rx_Buffer_Ptr Max_Serial_BD_Data_Length SerialTxBD Serial_TXBDindex Ready 1 else SerialTxBD Serial_TxBDindex Tx_Byte_Length Current_Tx_Byte_Length Current_Tx_Byte_Length 0 Ethernet Rx_Buffer_Ptr Current_Tx_Byte_Length SerialTxBD Serial_TXBDindex Ready 1 Getting another BD for the End of Sequence data packet Repeat if Serial_TxBDindex Max_Serial_RxBD_Size Serial_TxBDindex 0 else Serial_TxBDindex tt If SerialTxBD Serial_TxBDindex Ready 0 Found_free_serial_TxDB true Until found_free_serial_TxDB SerialTxBD Serial_TxBDindex Tx_Byte_Length EndOfPacketSequenceLength SerialTxBD Serial_TxBDindex Tx_Byte_Ptr Ethernet Rx_Buffer_Ptr SerialTxBD Serial_TXBDindex Ready 1 Increment the global variable indicating that 1 more data is ready for transmit DataReadyt t Enable the Serial interrupt so that when the CPM move the end of packet sequence it will fire the Serial ISR zal D 24 SerialTxBD Serial_TXBDindex Interrupt 1 Disassemble Function Ethernet_RX_BD_Cleanup Function
78. s IP address from content Send IP address to serial port along with a special sequence that this is a special packet for configuration IP only for serial retrieve routine If special IP packet Retrieve remote PC s IP from received data Program remote PC s IP into local board s IP else Normal retrieve routine endif D 3 3 MODULE DESCRIPTIONS D 3 3 1 Local data Variables Table D 4 Description of Local Variables used during Copy Module Variable Name Description int SerialRxBDindex The pointed entry in the Serial Receive BD table int Serial TxBDindex The pointed entry in the Serial Transmit BD table bool Found_free_serial_TxBD Flag to indicate that a free Serial Transmit BD buffer is found int Current_Packet_Length The data length of the current packet int Ethernet_RxBDindex int Ethernet_TxBDindex The pointed entry in the Ethernet Receive BD table The pointed entry in the Ethernet Transmit BD table bool Found_free_ethernet_TxBD Flag to indicate that a free Ethernet Transmit buffer is found D 3 3 2 Module Pseudocode Module Main Module Main Initialise Loop forever if Disassemble gt 0 call Disassemble function if call U nassemble gt 0 Assemble function D 21 Function Assemble Function Assemble found false repeat if SerialRxBDindex Max_SerialRxBD_Size SerialRxBDindex 0 else SerialRxBDin
79. s data has not been send yet The user should call ser_send int len to send out the data At the end of that send function the flag will be set to TRUE if ser_TxBufferPoolEmpty return NULL If the flag ser_TxBufferPoolEmpty is empty then return the address of the serial Tx Buffer Pool It also set the flag ser_TxBufferPoolEmpty to FALSE indicate that there will be data in the buffer that is not send ser_TxBufferPoolEmpty FALSE return ser_TxBufferPool 31 3 2 3 3 SER_SEND FUNCTION Table 6 Descriptions of Local Variables used in ser_send Function Variable Name Description int I Counter int j Counter char tempChar Temporary storage of a char char tempByteStr 3 Temporary storage of a byte Function ser_send int len This function will ONLY run if the Buffer Pool is NOT empty which means that there is some data in the buffer if s for ser_TxBufferPoolEmpty TRU er_TxBufferPoolEmpty i 0 i lt len itt while COM1 gt LSR amp LSR_TX_EMPTY tempChar ser_TxBufferPool i oneByteToAscii tempByteStr amp tempChar One Byte converted to 2 byte for sending ascii display for j 0 j lt 2 J spin if Tx holding register not empty while COM1 gt LSR amp LSR_TX_EMPTY send it out COM1 gt buf tempByteStr jl CI Table 7 Description of Loca
80. s not the last BD 1 buffer is the last BD bool interrupt flag to indicate interrupt generated after BD is processed 0 no interrupt generated 1 interrupt generated bool framing_error flag to indicate framing error has been received 0 no framing error current buffer 1 framing error is received for one character which is located in the last byte of the buffer a new Rx buffer is used to store subsequent data bool parity_error flag to indicate parity error has been receive 0 no parity error in current buffer 1 parity error is received for one character which is located in the last byte of the buffer a new Rx buffer is used to store subsequent data bool overrun flag to indicate overrun 0 no overrun occurred in current buffer 1 receive overrun occurred in data reception bool carrier_detect_lost flag to indicate carrier detect lost 0 no carrier detect lost 1 carrier detect signal is negated in data reception Data Length Bits int data_length 16 bits to indicate the length of data in buffer pointed by BD Buffer Pointer Bits int Tx_buffer_high_ptr 16 bits to indicate the higher order bits of starting address of the data in buffer pointed by BD int Tx_buffer_low_ptr 16 bits to indicate the lower order bits of starting address of the data in buffer pointed by BD Rx_BD D 18 D 3 2 SYSTEM INITIALIZATION Constants are us
81. s that have not been processed The total number of received Ethernet buffers that have not been processed The pointer to the currently processing Ethernet transmit buffer The pointer to the currently processing Ethernet receive buffer The pointer to the currently processing serial transmit buffer The pointer to the currently processing serial receive buffer The pointer to the first unprocessed serial RX BD The pointer to the first unprocessed Ethernet RX BD The pointer to the first disassembled but unsent Ethernet RX BD The pointer to the first assembled but unsent serial RX BD D 3 1 1 Description of Buffer Structure Before introducing other global structures the structure of a buffer is described first It is due to the fact that the Buffer Structure is an extremely important component of the WELA The data is stored in buffer and each buffer is referenced by a buffer descriptor BD Each BD is 8 bytes long Two bytes are used as control bits Two bytes are used to store the data length Four bytes are used to store the address of the memory location of the buffer Figure D 10 provides a representation of the buffer Tx Buffer Descriptors i Control Bits RxBD Table Pointer Buffer Length Buffer Pointer 3 gt Tx Buffer TxBD Table Pointer Rx Buffer Descriptors TxBD Table 4 7 Control Bits Buffer Length RxBD Table Buffer
82. s the safer and cleaner method for accessing the COM port in the Motorola Board This is because all the interrupts are grouped together by the Serial Interface SI block before sending it to the core processor This ensured that the interrupt are handled properly by priority However the initialisation instructions for the SMC stated in the user manual do not produce successful results and proper configuration of the SMC ot which registers value to set is unknown Therefore it is decided to access the ISA bus directly to get access to the COM 1 port 11 2 5 WIRELESS TRANSCEIVERS 2 5 1 MILESTONES ACHIEVED The wireless transceiver has been ordered and the test program provided along with the transceiver was used to verify its functionality It is necessary to verify that the transceiver can only operate at simplex mode 2 5 2 MILESTONES MISSED The development of the wireless transceivers is one of the milestones that have been missed Since the wireless transceivers are not considered as the main component of the project the amount of time and manpower assigned to them ate minimal Also when the transceiver was purchased it claims that it is very easy to use or simply plug and play However in the testing of the transceivers configuration procedures are needed in order to get a minimal error transmission By running the test program that comes with the transceiver the functionality of a simplex transmission is verified However in
83. semble function decrements assemble status variable to indicate the data packet stored in the buffer has been assembled 7 The Assemble function will link the data in the serial RX BD into a packet 8 After CPM processes a serial RX BD that contains the End of Packet Sequence it sets the Ready Bit of the Ethernet TX BD to indicate to the CPM that the packet is ready for transmission 9 The CPM will move the ready Ethernet TX BD s packet to the FIFO queue for transmission The ready bit of the Ethernet TX BD will be automatically cleared by the CPM after the packet is moved to the FIFO queue 10 The packet will get transmitted through the Ethernet interface 11 After the packet is transmitted the TX ISR will run to acknowledge the Serial Cleanup routine 12 The serial Cleanup routine will free up the buffer that holds the sent packet D 2 5 BLOCK DIAGRAM FOR THE COPY MODULE The following Figure D 6 shows the modular diagram of the Copy Module The Copy Module consists of four functions Disassemble Assemble Ethernet TxBD Cleanup and Serial TxBD Cleanup When new data packets arrive from the Ethernet port the disassemble function will partition the packets into smaller packets so that they can be handled by the serial interface After all the smaller partitions of an Ethernet packet are sent an ISR will notify the Ethernet RxBD Cleanup function to mark the Empty Status Bit of the BD for the Ethernet packet to 1 The valu
84. stapenetiateasaynansinexeaanbiayaeneeraveacydhesemsauasescaiiey 4 LAP Modifications and JustificationS sssssssseesissrisrissrisriseieseserieerissrisrreseese 4 2 2 3 1 BDs Modified In Ethernet Module Instead Of Copy Module 4 2232 gt MCCA ARP REDD iiin E N 5 29 Copy mod lesianiiiniiin iiini aaiae 5 ZIA Milestones PU CIUCU EE iis E EEE E EEE E EENE E 5 DoDD Milestones MISA ar an E AN a 5 2 3 3 Modifications and JustificationS ssssssssssessesissrisriseiserrseeererrriesrisrreseese 6 2 3 4 Disassemble block of the Copy module assesses 6 2341 Milestones Achieted siiin iain eia 6 2 3 4 2 Modifications and JustificationS sses 6 ZI Assemble Block OF The copy Module ssssssssssssisssisssiserrsereriserissrrssrrsere 7 23 3 1 Milestones Achieted aaneaiases te casas deltas Os iinan ana useaydes 7 2 3 5 2 Modifications And Justifications assesseer Z 2 4 Serial Titeffa e inina n a a as 9 24T Milestones Achieved iniii a 9 2 4 2 Modifications and JustificationS ssssssssssessserissrissrisriserrserererrriesrissrreseese 9 iv 2 5 Witeless Transceivers unnir a a a a N e 12 23 1 Milestones Acheved sanien a aesaat ie Atata 12 RIL Milestones Miseler a E NE E AET 12 2 5 3 Modifications and JustificationS sssssssssssssseseesisrrissrisrrisrisererererersreess 12 DA sein paw aereaeas aanesaseaaul quad ara a a a ann Design audit 3 1 High leyel designi eena Aa 16 3 1 1 Transmission of Data from Ethernet to Serial Interfate occscss
85. stated transfer rate is not possible because the CPM would not have enough time to process the incoming data Therefore we need to verify that the CPM utilization for our design is less than 100 G 4 SOFTWARE DELAYS The software delay is the delay introduced in executing the code in the datapath from the instance a packet is recetved from Ethernet port to the instance the packet is sent to the remote PC Each different type of instruction has a different latency and they are stated in the MPC860 user manual One can estimate the total delay in the datapath by estimating the composition of each instruction type encountered in the datapath multiplied by the estimated total number of instructions in the datapath The total delay is the estimated delay in transferring one 32 bit word of data Total ofInstructionsInDatapath x Total Delay DataTransfer amp gt LatencyforlnstructionType x InstructionType i l 1 Maximum Transfer Rate SS SS COO OO TotalDelay DataTransfer x 32bit datatransfer G 5 TRANSCEIVER The only way to verify that the transceiver can operate at a rate of 50kbps is to check the specification on the datasheet of the transceiver The transmission distance depends on the transceiver used in the design The transceiver must be verified that it is operational at a distance of 25 meters apart The exact approach used in the verification of the transmission rate of the transceiver can be
86. terrupt routine Eth_send sends the data in the current Ethernet Tx buffer Eth_recv polls the empty bit of the current RxBD and returns the current Rx buffer if a new packet has arrived Eth_setRxBufferEmpty sets the current Rx BD s empty flag Eth_getTxBuffer gets the current Tx buffer if it is ready for use The interrupt routine will be executed after a packet has been received from the computer into the Ethernet Interface During the execution of this interrupt the Copy Module will be notified that a new packet has been received and increment a counter that keep tracks of total number of packets stored in the Receive Buffer 3 1 6 SERIAL INTERFACE The serial Interface module contains four API functions Ser_send sends the data in the current serial Tx buffer Ser_recv polls the data ready bit of the current serial status register and copy the current byte to receive buffer in main memory It keeps copying new serial bytes to receive buffer until the EOS is detected Eth_setRxBufferEmpty sets the current Rx BD s empty flag Eth_getTxBuffer gets the current Tx buffer if it is ready for use The interrupt routine will be executed after a packet has been received from the computer into the Ethernet Interface During this interrupt routine the Copy Module will be notified about the data length of this new set of serial data for the reconstruction of different sets of serial data into one complete packet 3 1 7 GETLOCALIP PROC
87. the other Table 9 shows the basic essential customer requirements satisfied at this stage in time Appendix I shows the demonstration results to faculty member Roger Sanderson Table 9 Functional Test and Verification Results Test Components tested Test procedure Result ARP test ARP reply feature Verify PC s ARP table does not Pass Ethernet transmit contain the entry for the local board and receive 2 Ping local board from PC 3 Check ARP table of PC It should contain entry which maps IP address with the board s hardware address Serial unit Serial transmit and 1 Write a test program which echo Pass Test receive received serial character 2 Run the test program on board Type characters to the console port You should see the characters echo onto the screen Send Ethernet receive 1 Run our program on board Pass Ethernet serial transmit copy 2 Ping board from PC packets module s disassemble 3 An ASCII version of the ping from PC function packets should show up on console port Send ASCII Ethernet transmit 1 Run program on board Pass packet from serial receive copy 2 Run packet monitor program on PC console module s assemble 3 Send pre defined valid ASCII packet port function which represents textual version of a valid Ethernet packet 4 The PC s packet monitor program should show the same packet appearing at the Ethernet interface 34 NULL modem connects tw
88. ther modules can only access those buffers through API function calls For example the Tx and Rx BDs cannot be directly accessed by the Copy module instead the Copy module must call functions to obtain access to the Tx buffer or to set the BD empty bits Table 3 provides the modified module descriptions for the prototype design Table 3 Module descriptions Module Description Serial_ Interface The Serial Block is used to transmit or receive data from the serial port It consists of receive and sending API function which other modules can call It also contains an internal Tx and Rx buffer pool which is used to hold data to be transmitted or received from serial port To use these buffers certain flags must be set and API functions are provided to modify the flags 16 Ethernet_Interface Copy_Block Initialization The Ethernet ISR Block is used to transmit or receive data from the Ethernet interface It contains buffers to hold data and it contains an interrupt ISR to service interrupts generated by events related to the Ethernet port This module is also responsible for modifying Ethernet BDs When new data is received from the Ethernet port an interrupt will be generated after new data is copied to a buffer External modules can access the data by calling API send or receive functions The Copy Block is used to coordinate the data manipulation between the Ethernet port and the serial port It will call the interface s re
89. there are several modifications made since after the interim report 2 3 4 2 MODIFICATIONS AND JUSTIFICATIONS The most significant change is that the serial BD structure no longer exists The reason for this is because a different method for the serial interface transmission was used For further details of the justifications for the required changes in the serial interface please refer to Section 2 4 Thus instead of performing inspection of the ready data in the serial FIFO all the code for the validation was moved into the serial interface The reason for that is to keep the code as modular as possible thus the modification of the serial buffer should be left to the serial interface The above decision greatly simplified the Disassemble block The Copy module was made responsible to call functions in the Ethernet interface to check for incoming Ethernet data In another word when the Disassemble function is called by the Copy module there must be data presents in the Ethernet receive buffer that is ready to be disassembled This further simplified the Disassemble block and increased the modularity of the whole system It is decided upon to simplify the Disassemble Block due to the priority to have high code modularity The Disassemble Block should only take received Ethernet data and transfer them into Serial transmit data The accessing of the control bits i e the empty flag for the buffer should be left to the Serial interface A
90. upts will be enabled and finally the GetLocalIP procedure will be executed before returning to the main routine D 2 7 ETHERNET INTERFACE The Ethernet Interface module contains one interrupt routine that is executed under one condition The interrupt routine will be executed after a packet has been received from the computer into the Ethernet Interface During the execution of this interrupt the Copy Module will be notified that a new packet has been received and increment a counter that keep tracks of total number of packets stored in the Receive Buffer D 2 8 SERIAL INTERFACE For the Serial Interface module there is one interrupt routine that will be executed under one condition For the interrupt routine it is executed after a set of serial data has been received from the serial interface During this interrupt routine the Copy Module will be notified about the data length of this new set of serial data for the reconstruction of different sets of serial data into one complete packet D 2 9 GETLOCALIP PROCEDURE During the final stage of system initialization the GetLocalIP procedure will be executed This procedure is executed for the exchange of IPs between the two wireless Ethernet adapters At this stage of system initialization the two wireless Ethernet adapters have been powered up and communication links can be established with their attached computer The wireless Ethernet adapters will first request the IP of their assoc
91. used That is check the specification of the datasheet of the transceiver APPENDIX H PROTOTYPE TEST MEASUREMENT DATA A continuous stream of packets is sent to Ethernet port After processing the packets are outputted to the console port The WELA is able to accept data at 0 1 second packets This equates to 10 packets per second Every packet that was sent are 102 bytes long Thus 1020 bytes of information are sent per second or 8160 bits per second However there is a loss of about 1 packet for every 20 packets sent This equates to an packet error rate of about 5 The console port is capable of transmitting data at 9600 bits per second The figure we got is slight lower than this due to the internal processing APPENDIX I DESIGN AUDIT PROTOTYPE DEMO l 2 I 3
92. xBD Ethernet_TxBDindex Ready 1 else Current_Packet_Length Serial Rx_Byte_Length of unprocessed BD Serial Rx_Byte_Ptr Serial Rx_Byte_Length of unprocessed BD Unassemble Function Disassemble Function Disassemble found false repeat if Ethernet_RxBDindex Max_Ethernet_RxBD_Size Ethernet_RxBDindex 0 else Ethernet_RxBDindextt Find next unprocessed BD in Ethernet RxBD table It is guaranteed that there will be at least 1 Non empty entry else this function won t be called a7 if EthernetRxBD Ethernet_RxBDindex Empty 0 ica thernet Rx_Buffer_Ptr EthernetRxBD Ethernet_Rx_BDindex Buffer_Ptr thernet Rx_Buffer_Length EthernetRxBD Ethernet_Rx_BDindex Length found true K ra until found found_free_serial_TxDB false find an empty serial Tx slot to store the serial data If there are not free Tx slot this will loop forever Meanwhile the CPM will keep processing data in background and update the BD Hopefully there will be an empty slot eventually xf Repeat if Serial_TxBDindex Max_Serial_RxBD_Size Serial_TxBDindex 0 D 23 else Serial_TxBDindextt If SerialTxBD Serial_TxBDindex Ready 0 Found_free_serial_TxDB true Until found_free_serial_TxDB Current_Tx_Byte_Length Ethernet Rx_Buffer_Length SerialTxBD Se

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