Calibre UK PICA93LV Network Card User Manual
Contents
1. 0 then the data has been sent if PIN 1 then it has not When receiving data if PIN 0 then there is unread received data ready to read if PIN 1 then either the data received has already been read or no data has yet been received Bit 6 Not Used This bit is not currently used and will always 0 Bit 5 The STS Bit When in slave receiver mode i e transmission initiated by a master elsewhere on the 12C bus the flag STS 1 when an externally generated Stop condition is detected otherwise STS 0 This flag is used only in slave receiver mode Bit 4 The Bus Error BER Bit BER 1 when a misplaced Start or Stop has been detected otherwise BER 0 This can be quite serious since the I2C devices on the bus may be left in an undefined state after a bus error has occurred in some circumstances the only way to get the bus going again may be to reset all the 12C devices on it Bit 3 The Last Received Bit Address 0 General Call Address Received LRB ADO Bit This dual function status bit holds the value of the last received bit over the I2C bus when AAS Bit 2 0 Normally this will be the value of the slave acknowledge thus checking for slave acknowledgement is done via testing of the LRB bit When AAS Bit 2 1 Addressed As Slave the Parallel I2C Communications Adapter has been addressed as a slave and the ADO bit will 1 if the slave address received was the General Call address For further information on th2. CALIBRE When all the bytes have been transmitted a stop is issued and the total number of bytes is returned Sendbytes can only be used in master write mode Int getbytes int far transferarray int far transferarray The far pointer must point to a single dimensional array the format of which is detailed below The calling function must have initialised elements 0 1 and 2 prior to calling the function Element name Description slaveaddress Slaveaddress is the address to be accessed via the I2C Bus this is in hexadecimal e g AOH wordaddress Wordaddress is the offset within the slave to which the first byte of data is to be written see transmission format for more detail nobytes The number of bytes n to be sent Min value 1 byte 0 First byte read byte n Last byte read int nobytesread The number of bytes actually read Adapter must be configured using setup Array elements 0 1 and 2 must be initialised Elements 3 to n do not need to be initialised since they are where the read data is returned The array must be pre defined to a size at least large enough to hold all the parameters and data concerned If the slaveaddress has the least significant bit set 1 then this forms a read address if the least significant bit is clear 0 then this forms the write address e g AOH is the write address and A1H is the associated read address getbytes supports two transfer formats these being i start slaverea
3. Parameters are None Value Returned int i2cstatus where i2cstatus is an integer from 0x00 to OxFF which indicates the current status of Parallel 2 Communications Adapter See Appendix A for details of the status values returned I2C status on exit the status of the Parallel 12C Communications Adapter will not be affected by using the getstatus function Example Usage see also sample programs main int i2cstatus i2ctatus getstatus printf Parallel 12C Communications Adapter Status x n i2cstatus This will read the Parallel 12C Communications Adapter s current status 4 2 3 l2C Address and Start Sending Routine Function definition int sendaddress int slaveaddress int setnack Usage i2cstatus sendaddress slaveaddress setnack Function This is the procedure to send Start and slave address of device which is to be communicated with Parameters are int slaveaddress The 8 bit slave address of the device which is to be communicated with This will be an even number if the adapter is to write to the slave add 1 to get an odd number if the adapter is to read from the slave int setnack This controls whether the Parallel 12C Communications Adapter transmits an Acknowledge down the I2C Bus on reception of a byte The last byte received during a transfer must not be acknowledged If setnack 0 then acknowledge is enabled if setnack 1 then acknowledge is disabled Therefore if a read odd numbe
4. function prototypes win c lpti2c lib 12C C library win vb3O lpti2c bas Visual Basic 3 0 declarations win vb3O lpti2c dll I2C Visual Basic dynamic link library The following functions are implemented in the windows libraries void far pascal _export setup int baseaddress int ownaddress int sclk int statuswait int far _pascal _export sendaddress int slaveaddress int setnack int far _pascal _ export restart int slaveaddress int setnack int far_pascal export getstatus void int far_pascal _export writebyte int wrData int far_pascal _export readbyte int setnack int far_pascal _export sendstop void int far_pascal _export recover void int far_pascal export sendbytes int __far transferarray int far_pascal export getbytes int __far transferarray void far pascal export slavelastbyte void Issue 1 3 Page 6 22 07 99 USING THE UTILITIES 4 1 Introduction Each utility is documented in a standard format which lists its name usage function and effect on the adapter is given The adapter should be setup prior to any data transfer 4 2 C Routines 4 2 1 12C Setup Initialisation Routine Function definition void setup int ownaddress int sclk Usage setup ownaddress sclk Function procedure to set up Parallel 12C Communications Adapter Parameters are int ownaddress The address to which the adapter is to respond in slave mode This forms the upper 7 bits of the 8 bit address the
5. x n i2cstatus 4 2 7 l2C Restart and Address Sending Routine Function Definition Usage Function Issue 1 3 22 07 99 int restart int slaveaddress int setnack i2cstatus restart slaveaddress setnack This is the procedure to send Restart and slave address of device which is to be communicated with without a Stop having been sent at the end of last transmission reception This routine is particularly useful for reading memories which must first have a data pointer written to them to select where the read is to occur from and must have their address sent a Restart to proceed with the read operation Page 12 Parameters are Value Returned I2C status on exit Example Usage CALIBRE CALIBRE int slaveaddress The slave address of the device which is to be communicated with This will be an even number if the adapter is to write to the slave add 1 to get an odd number if the adapter is to read from the slave int setnack This controls whether the Parallel 12C Communications Adapter transmits an Acknowledge down the 12C Bus on reception of a byte The last byte received during a transfer must not be acknowledged in all other cases acknowledge must be enabled If setnack 0 then acknowledge is enabled if setnack 1 then acknowledge is disabled Therefore if a read odd numbered address is being sent AND only 1 byte is to be read setnack should be set to 1 in all other cases it must be clea
6. 1 3 Page 15 22 07 99 Sub Main CALIBRE CALIBRE slaveaddress amp HAO IC Address of slave this is a typical write setnack 0 address for an 12C static RAM or EEPROM Enable Acknowledge see parameter descriptions i2cstatus sendaddress slaveaddress setnack Select Case i2cstatus case amp H00 print Start and I2C Slave Address sent and acknowledged case amp H08 print Start and I2C Slave Address sent and not acknowledged case else End Select End sub print Start not sent status is Hex i2cstatus 4 3 4 12C Read Data Byte from Slave Routine Function definition Usage Function Parameters are Value Returned 12C status on exit Issue 1 3 22 07 99 readbyte setnack as integer i2cdata readbyte setnack function to read a byte of data from a slave device whose slave address has already been sent by sendaddress Can be used to disable acknowledge after reading data if it is the last but one byte to be read setnack This controls whether the Parallel 12C Communications Adapter transmits and Acknowledge down the 12C Bus on reception of a byte The last byte received during a transfer must not be acknowledged in all other cases acknowledge must be enabled If setnack 0 then acknowledge is enabled if setnack 1 then acknowledge is disabled Therefore if the LAST BUT ONE byte is to be read setnack should be set to 1 in all other cases it mu
7. 2 Bus Capacitance Limitations The maximum allowable capacitance on the 12C bus in normal mode depends on the value of the SCL and SDA master pull ups but never exceeds 400pF Refer to Phillips Technical Handbook Book 4 Parts 12a and 12b for further details see Further Information for references Care should be taken in choosing a length and type of interconnecting cable which will not exceed this limit 2 3 Power Supply Pin 7 on the D connector is connected to the PICA93LV power supply This supply is fitted with overload protection and up to 0 250mA can be drawn from here When shipped to you the bus voltage was factory pre set to 3 3V for use with low voltage memories You can adjust the voltage by inserting a small screwdriver through the hole in the front panel Your PICA93LV has been factory set for use on 3 3V I2C bus systems Use on 5V I2C bus systems without adjusting the voltage WILL CAUSE PERMANENT DAMAGE to the PICAQ3LV The fault is factory detectable and you WILL BE CHARGED FOR THE REPAIR 2 4 Resetting the Adapter Each time the PICA93LV is re configured via the Setup function it is automatically reset by software Issue 1 3 Page 3 22 07 99 SOFTWARE UTILITIES 3 1 Introduction Unpack the software from the CD ROM in accordance with the instructions provided with the licence The Software utilities contain simple DOS routines in both C QBASIC and Windows DLL LIB 16bit only for use with Visual Basic and Mic
8. Routine Function definition Usage Function Parameters are Value Returned 12C status on exit Example Usage int sendstop void i2cstatus sendstop This is the procedure to send a stop end of communication signal down the I2C Bus ending a transmission or reception with a slave which was addressed previously by sendaddress None int i2cstatus The value returned depends on whether the bus became free If the bus became free then the status 0x81 is returned If the bus does not became free then the last status read IORed with 0x8000 will be returned The function will read the status a number of times waiting for the bus to become free before returning an none free status this number is defined by the MAXNUMBEROFGOES constant defined in l2CINC C this value may be altered to suit your system The status of the Parallel 12C Communications Adapter will be 0x81 bus idle and no unread untransmitted data in data register Note this may not be the case in a system where there is another master as well as the Parallel 12C Communications Adapter since this other master may well have taken control of the bus by the time a program next uses getstatus to read the status register See Appendix A for details of status codes see also sample programs This will write a Stop to the 12C Bus main int i2cstatus i2cstatus sendstop printf Stop has been transmitted status is
9. lowest bit being the Read 1 or Write 0 bit This means that if own 0x57 the card will respond to a Write to address OxAE and a Read to address OxAF Be sure not to select an address which is already in use by any other device in your I2C system int sclk The SCL clock rate bit rate for 12C serial bus Value of sclk Approximate SCL KHz 0 90 1 45 2 11 3 1 5 Value Returned none 12C status on exit I2C status on exit from routine the Parallel 12C Communications Adapter will have the serial interface enabled also data reception acknowledge will be enabled The status register will contain 0x81 assuming that no other masters exist on the I2C system if this is not the case then the contents of the status register will also depend on externally generated bus activity Example Usage see also sample programs main int ownaddress sclk ownaddress 0x57 Own slave address set to 0x57 hex sclk 1 Serial clock rate set to 45KHz setup ownaddress sclk printf Parallel 12C Communications Adapter initialised n This will set up the Parallel 12C Communications Adapter with an 12C slave address of OxAE and a SCL clock rate of approximately 45KHz Issue 1 3 Page 7 22 07 99 CALIBRE CALIBRE 4 2 2 12C Status Checking Routine Function definition int getstatus void Usage i2cstatus getstatus Function function to read status register of the Parallel 12C Communications Adapter
10. only 1 Byte is to be read setnack should be set to 1 in all other cases it must be clear 0 int 12CData The data read if a time out occurs the ErrCode 8005H is returned Adapter must be configured using setup start and read address sent by sendaddress If setnack is 1 the function writes 40H to the control register to establish the correct acknowledge procedure The data is read from the adapter Should a time out occur then an error code 8005H is returned otherwise the data is returned Readbyte is compatible with both master read and slave read modes Int sendstop None int ErrCode lf the transfer time out occurs error code 8002H is returned otherwise the status is returned Adapter must be configured using setup Should normally only be used at the end of a transmission Correct acknowledge sequence must have been applied if the transmission was a read Instruct the adapter to send a stop code and wait for it to be sent Should a time out occur during the sending of a stop then an error code 8002H is returned otherwise the status is returned Page 22 4 4 9 restart Function specification Parameters are Parameters returned Prerequisites Functional description 4 4 10 getstatus Function specification Parameters are Parameters returned Prerequisites Functional description 4 4 11 recover Function specification Parameters are Parameters returned Prerequisites Issue
11. restart transmission without releasing control of the 12C bus The address to be sent is placed in the data register after sending the start code To execute the last four instructions with acknowledge disabled i e negative acknowledge nack send the control code 1 e g 0x40 0x44 0x46 Issue 1 3 Page 29 22 07 99 6 1 Question Answer Question Answer Question Answer Question Answer Question Answer 6 2 Question Answer 6 3 Question Answer Question Answer Issue 1 3 22 07 99 CALIBRE CALIBRE THE MOST COMMONLY ASKED I2C QUESTIONS General Questions Will my adapter run I2C clock speeds greater than 90KHz At the moment your adapter is limited by the Bus Controller chip fitted to a maximum of 9OKHz as a master and 100KHz as a slave Will my adapter work under Windows NT4 or Windows 95 The adapter will work under both these systems without problems If you need to access the Windows NT and Windows 95 DLLs please contact our sales team for further information All trade marks acknowledged I get corrupted transfers why is this The most likely reason for corrupted transfers is either incorrect bus termination or excessive capacitance see the manual for details Do you have software to talk to my Unfortunately there are too many I2C devices for us to be able to offer complete solutions although we can supply a windows based application called WI
12. sclk print Parallel 12C Communications Adapter initialised end sub 4 3 2 12C Status Checking Routine Function definition getstatus Usage I2Cstatus getstatus Function function to read status register of Parallel 12C Communications Adapter Parameters are None Value Returned i2cstatus where i2cstatus is an integer from amp H00 to amp HFF which indicates the current status of the PICA93LV Issue 1 3 Page 14 22 07 99 CALIBRE CALIBRE See Appendix A for details of the status values returned I2C status on exit The status of the Parallel 12C Communications Adapter will not be affected by using the FNgetstatus function Example Usage see also sample programs This will read the Parallel 12C Communications Adapters current status sub main i2cstatus getstatus print Parallel 12C Communications Adapter Status hex i2cstatus end sub 4 3 3 l2C Address and Start Sending Routine Function definition sendaddress slaveaddress as integer setnack as integer Usage i2cstatus sendaddress slaveaddress setnack Function procedure to send Start and slave address of device which is to be communicated with Parameters are slaveaddress The slave address of the device which is to be communicated with This will be an even number if the adapter is to write to the slave add 1 to get an odd number if the adapter is to read from the slave setnack This controls whether the Parallel 12C Comm
13. 1 3 22 07 99 CALIBRE CALIBRE Int restart int slaveaddress int setnack int slaveaddress The address to be accessed via the 12C e g A1H int setnack This controls whether the Parallel 12C Communications Adapter transmits an Acknowledge down the 12C Bus on reception of a byte The last byte received during a transfer must not be acknowledged in all other cases acknowledge must be enabled If setnack 0 then acknowledge is enabled if setnack 1 then acknowledge is disabled Therefore if a read odd numbered address is being sent AND only 1 Byte is to be read setnack should be set to 1 in all other cases it must be clear 0 int ErrCode If the transfer time out occurs error code 8003H is returned otherwise the status is returned Adapter must be configured using setup A start and slave address must have previously been sent using sendaddress Usually a data pointer would already have been written using writebyte Sends a start code and the slave address specified and presets the acknowledge status depending on the value of setnack The acknowledge is set ready for the data transfer after the address and hence in read mode odd address being sent if only one byte is to be read the setnack parameter must equal 1 If more than one byte is to be read or if in write mode even address being sent then setnack must equal 0 The function waits for the address to be sent Should a time out occur during the sending of
14. BRE Windows 95 START Run regedit HKEY_LOCAL_MACHINE SYSTEM CurrentControlSet Services Class WinRT WinRTdev0 Parameters SectionO Section1 Windows NT START Run regedit HKEY_LOCAL_MACHINE SYSTEM CurrentControlSet Services WinRT WinRTdev0 Parameters SectionO Section1 Question I am using your Windows 95 NT DLL and I am always getting a time out error code Why Answer Check the Syntax of the setup function this problem is most usually caused by swapping the Status Wait and Sclk parameters The correct syntax is i2cstatus setup baseaddress ownaddress sclk statuswait Question have read the manual and still cannot get the communications to run What do I do next Answer Check that you have fully implemented the protocol between the adapter and the other 12C devices see the device manufacturers data sheet for details Check that the software you have written is logically and syntactically correct this is probably the most common cause of software faults we have to deal with Send us the following details 1 The link settings of the adapter 2 A sketch of the relevant 12C hardware including the location of bus termination 3 The type and speed of processor within your PC and which operating system you are running Issue 1 3 Page 31 22 07 99 CALIBRE CALIBRE 4 Brief software listings or which Calibre soft
15. CALIBRE PICA93LV Parallel 12C Communications Adapter User Manual 22 07 1999 Calibre UK Limited Cornwall House Cornwall Terrace Bradford West Yorkshire BD87JS England Tel No 01274 394125 FAX No 01274 730960 E mail Gales calibreuk com Web site lwwwcalibreuk coml Welcome to the Calibre parallel I C interface This interface is designed to allow users to run PC Bus operations via PC parallel port If you have any queries relating to this or any other FC product supplied by Calibre please visit our web site For technical support please e mail techsupport calibreuk com or send your queries by fax to 44 1274 730960 for the attention of our I C Technical Support Department COPYRIGHT This document and the software described within it are copyrighted with all rights reserved Under copyright laws neither the documentation nor the software may be copied photocopied reproduced translated or reduced to electronic medium or machine readable form in whole or in part without prior written consent of Calibre UK Ltd Calibre Failure to comply with this condition may result in prosecution Calibre does not warrant that this software package will function properly in every hardware software environment For example the software may not work in combination with modified versions of the operating system or with certain network adapter drivers Although Calibre has tested the software and reviewed the documentation
16. CALIBRE MAKES NO WARRANTY OR REPRESENTATION EITHER EXPRESS OR IMPLIED WITH RESPECT TO THIS SOFTWARE OR DOCUMENTATION THEIR QUALITY PERFORMANCE MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE THIS SOFTWARE AND DOCUMENTATION ARE LICENSED AS IS AND YOU THE LICENSEE BY MAKING USE THEREOF ARE ASSUMING THE ENTIRE RISK AS TO THEIR QUALITY AND PERFORMANCE IN NO EVENT WILL CALIBRE BE LIABLE FOR DIRECT INDIRECT SPECIAL INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE SOFTWARE OR DOCUMENTATION even if advised of the possibility of such damages In particular and without prejudice to the generality of the foregoing Calibre has no liability for any programs or data stored or used with Calibre software including costs of recovering such programs or data Copyright Calibre UK Ltd c 1999 Cornwall House Cornwall Terrace Bradford BD8 7JS UK E mail Sales calibreuk com Web site All World wide Rights Reserved 22 07 1999 All trade marks acknowledged Calibre operates a policy of continued product improvement therefore specifications are subject to change without notice as products are updated or revised E amp OE Issue 1 3 22 07 1999 CALIBRE CALIBRE Contents INTRODUCTION 1 General Introduction 2 Packing List 3 Configuring the Adapter 4 Bus Termination and Protection Resetting the Adapter Introduction DOS C Library Programs 3 DOS QBAS
17. IC Library Programs 4 Windows LIB DLL Functions y a ae th Gd Keo e 2 S N OO GO Oo aN OO Foy AIR AI NIN olojo OC OOFNFO Issue 1 3 Page i 22 07 99 CALIBRE CALIBRE INTRODUCTION 1 1 General Introduction The Parallel 12C Communications Adapter is designed to connect to any IBM PC compatible parallel port It is based on the Philips PCF8584 bus controller it features full 12C bi directional compatibility as either a master or slave I2C connections are made via a 9 way D socket 1 2 Packing List Your Parallel 12C Communications Adapter is supplied with the following items A I2C CD ROM B The PICA93LV unit the actual adapter C A cable set 1 25 way parallel cable 2 6 pin mini DIN male gt 6 pin mini DIN male 3 5 pin DIN female gt 6 pin mini DIN male 4 6 pin mini DIN female gt 5 pin DIN male 1 3 Configuring the Adapter NOTE MANY COMPONENTS ON THE ADAPTER CARD ARE STATIC SENSITIVE OBSERVE NORMAL STATIC SENSITIVE PRECAUTIONS WHEN HANDLING THE CARD The adapter is supplied in a standard configuration which should suit most applications However the bus termination and protection are link selectable Read the following section to change the configuration The standard configuration is bus termination and protection off 1 4 Bus Termination and Protection Normally the system to which the Parallel 12C Communications Adapter is to be
18. NI2C which is designed for those just starting 12C or wishing to perform simple 12C tasks please contact our sales team or look on our web site www calibreuk com for further information am trying to read from a device the first time my software works fine but when I try again I can t get anything what s wrong Please check that you are changing the value of Setnack in accordance with the manual it is likely that you have not made Setnack 1 for the last AND last but one bytes being read DOS Software Questions My I2C adapter locks up with a constant status why If you are using either the C or Basic library functions supplied with the adapter on a fast PC it is possible that the PC is polling the status register too quickly the simplest way to prevent this is to add a small delay prior to reading the status in the getstatus routine Alternatively use the windows DLL supplied as these automatically allow for speed of the PC at run time WINDOWS 95 and NT Questions My software cannot find the adapter Your Windows software reports that it cannot configure the adapter Why is this Have you registered the device driver as detailed in the software manual If so check that the address links see adapter manual for details are correct for the location at which you registered the driver I think I have registered the driver how can find out if have You need to inspect the registry as follows Page 30 CALIBRE CALI
19. an address then an error code 8003H is returned otherwise the status is returned Int getstatus void None int l2Cstatus The current value of the bus status Adapter must be configured using setup The function reads status word from the adapter and returns it Int recover void None int ErrCode If the bus recovery failed error code 8006H is returned otherwise the status is returned Adapter must be configured using setup Page 23 Functional description 4 4 12 sendbytes Function specification Parameters are Element no 0 Parameters returned Prerequisites Transmission format Functional description Issue 1 3 22 07 99 CALIBRE CALIBRE This function issues two consecutive stop commands on the bus with a delay in between It then clears the adapter registers and reads the status This should normally set the adapter into a known idle state when a bus error or other problem has occurred If the status does not indicate bus free or the bus Error bit is still set then 8006H is returned otherwise the status is returned Int sendbytes int far transferarray int far transferarray The far pointer must point to a single dimensional array the format of which is detailed below The calling function must have initialised elements 0 1 and 2 prior to calling the function Element name Description slaveaddress Slaveaddress is the address to be accessed via the I2C Bus this is in hexadecimal
20. ata sheet is correct the only exception is that a Stop should be sent as C3 Hex as shown in the application not 43 hex implied in the data sheet see Appendix B of this manual for details of control codes Where in doubt follow this manual Issue 1 3 Page 27 22 07 99 CALIBRE CALIBRE APPENDIX A Parallel I2C Communications Adapter Status Codes This is an eight bit register read using the getstatus routine The bit definitions are as follows Bit 7 MSB The Pending Interrupt Not PIN Bit The PIN bit is a read only flag which is used to synchronise serial communication Each time a serial data transmission is initiated by sendaddress routine or setting STA bit the PIN will be set 1 automatically After successful transmission of one byte 9 clock pulses including acknowledge this bit will be automatically reset 0 indicating a complete transmission When the ENI bit enable interrupt is also set the PIN triggers an external interrupt via the selected IRQ line when PIN is reset When in receiver mode the PIN is also reset on completion of each received byte In polled applications the PIN bit is tested using the getstatus routine to determine when a serial transmission has been completed In receiver mode the PIN bit is tested using the readbyte function When the PIN becomes set all other status bits will be reset with the exception of the BB not Bus Busy bit In short when transmitting data if PIN
21. connected should already have master pull up resistors fitted to the SCL and SDA lines If this is not the case LK6 and LK7 can be used to connect 4 7K pull up resistors to the 5V supply on these lines The standard configuration is with these resistors disconnected The SCL and SDA lines are protected by 100R series resistors before exiting the adapter via the 9 way D socket Upstream of the series resistors the SCL and SDA pins on the PCF8584 are pulled up with high value resistors 10K These ensure that the 12C Bus is in a defined state even if no other devices are connected LK4 and LK5 connect optional protection diodes to the SCL and SDA lines When selected these lines are clamped to the OV and 5V lines giving protection against transients If these diodes are connected the external 12C system will not function if the adapter is connected but not powered up The standard configuration is with these diodes disconnected Issue 1 3 Page 1 22 07 99 CALIBRE CALIBRE 1 5 Installing the Adapter Connect the PICA93LV to your PC as shown in figure 1 the cable numbers correspond to the packing list above Figure 1 0 TYPICAL PC CONNECTION Issue 1 3 Page 2 22 07 99 CONNECTING THE ADAPTER TO YOUR SYSTEM 2 1 Connector Pinout All external connections are made via a 9 way D socket Pin Normal Mode OV OV OV OV NC SDA Bi directional 5V SCL Bi directional NC oO ON OO FF W PD 2
22. d if Exit Sub 4 3 5 Write Data Byte to Slave Routine Function definition Usage Function Parameters are Value Returned 12C status on exit Issue 1 3 22 07 99 writebyte i2cdata as integer i2cstatus writebyte i2cdata procedure to write a byte of data to a slave device whose slave address has already been sent by sendaddress i2cdata The byte of data which is to be written to the slave device The value returned depends on whether the data was written successfully If the data was written then the status is returned If the data cannot be written then the last status read ORed with amp H8000 will be returned The function will read the status a number of times before returning an error condition this number is defined by the MAXNUMBEROFGOES constant defined in I2ZCINC BAS this value may be altered to suit your system amp HOO bus busy and data transmitted and acknowledged successfully amp HO08 bus busy and data transmitted successfully but not acknowledged amp H80 bus busy and data not transmitted See Appendix A for details of Status codes Page 17 Example Usage CALIBRE CALIBRE see also sample programs This will write a byte of data to a slave previously addressed by sendaddress Sub main i2cdata amp H69 Data byte which is to be transmitted i2cstatus writebyte i2cdata if i2cstatus and amp H8000 amp H8000 then print Data has not been tra
23. daddress byte s stop To select transfer format i pass the read address as slaveaddress The wordaddress is not used in this format and is ignored by getbytes ii start slavewriteaddress wordaddress restart slavereadaddress byte s stop To select transfer format ii pass the write address as slaveaddress In this format the wordaddress must be valid wordaddress is pointer to the first byte of data to be read nobytestoread is the number of bytes to be read The minimum value allowable is 1 Page 25 Functional description 4 4 14 slavelastbyte Function specification Parameters returned Prerequisites Functional description Issue 1 3 22 07 99 The function determines the required transfer format sends the appropriate sequence of start s and slave address es and checks for acknowledges where necessary If the slave fails to acknowledge then a stop is sent and nobytesread is returned equal to 0 The first data byte read is the slave read address sent see readbyte description This is discarded it is not returned in the transfer array The data bytes are then read and stored in the transfer array At the appropriate point acknowledges are ceased for the last and the last but one byte to be transferred A stop is sent after the last byte has been read On completion the number of bytes read is returned Should a time out occur the transfer is terminated by a stop and the number of bytes successfully read i
24. e General Call Address see the Philips data books referenced in Further Information Section of this User Manual Bit 2 The Addressed As Slave AAS Bit When acting as a slave receiver this flag is set 1 when an incoming address over the I2C bus matches the value defined by the setup routine or if the slave address received was the 12C bus General Call address 00 Hex In all other circumstances AAS 0 Bit 1 The Lost Arbitration Bit LAB This bit is set 1 when in multimaster operation more than one master present on the 12C bus arbitration is lost to another master on the 12C bus In all other circumstances LAB 0 Bit 0 The Busy Bit BB This is a read only flag indicating when the 12C bus is in use BB 0 indicates that the bus is busy and access is not possible unless of course it is busy because the Parallel 12C Communications Adapter itself has control of the bus This bit is set 1 by Stop conditions and reset 0 by Start conditions In short BB 1 means that the bus is free and a new transmission can be started Issue 1 3 Page 28 22 07 99 CALIBRE CALIBRE APPENDIX B Parallel I2C Communications Adapter Control Codes The Control Register should normally be written using the setup sendaddress and sendstop routines To implement more advanced functions for example enabling hardware interrupt generation these routines may need to be modified or the users own routines used in their place T
25. e 12C Bus sub main i2cstatus sendstop print Stop has been transmitted status is HEX i2cstatus end sub Issue 1 3 22 07 99 Page 18 CALIBRE CALIBRE 4 3 7 l2C Restart and Address Sending Routine Function definition restart slaveaddress as integer setnack as integer Usage i2cstatus restart slaveaddress setnack Function procedure to send Restart and slave address of device which is to be communicated with without a Stop having been sent at the end of the last transmission reception This routine is particularly useful for reading memories which must first have a data pointer written to them to select where the read is to occur from and must then have their read address sent with a Restart to proceed with the read operation Parameters are slaveaddress The slave address of the device which is to be communicated with This will be an even number if the communicated with This will be an even number if the adapter is to write to the slave add 1 to get an odd number if the adapter is to read from the slave setnack This controls whether the Parallel 12C Communications Adapter transmits an Acknowledge down the 12C Bus on reception of a byte The last byte received during a transfer must not be acknowledged in all other cases acknowledge must be enabled If setnack 0 then acknowledge is enabled if setnack 1 then acknowledge is disabled Therefore if a read odd numbered address is being
26. e g AOH wordaddress Wordaddress is the offset within the slave to which the first byte of data is to be written see transmission format for more detail nobytes The number of bytes n to be sent Min value 1 byte 0 First byte to be sent byte n Last byte to be sent int bsent The number of bytes actually sent Adapter must be configured using setup Array elements 0 1 and 2 must be initialised Usually elements 3 to n would also be initialised Array must be pre defined to a size at least large enough to hold all the parameters and data concerned There are two transmission formats these are i start slaveaddress byte s stop If transmission format i is required set the wordaddress to a number greater than FFH ii start slaveaddress wordaddress byte s stop If transmission format ii is required set the wordaddress to a number less than or equal to FFH The function determines the required transmission format and then sends a start code and the slave address If transmission format ii has been selected the wordaddress is sent The data bytes are then transmitted sequentially Should a time out occur or the slave not acknowledge a transfer the transmission is terminated by a stop and the number of bytes actually transmitted is returned Page 24 4 4 13 getbytes Function specification Parameters are Element no 0 Parameters returned Prerequisites Transmission Format Issue 1 3 22 07 99 CALIBRE
27. erating as a master Value of sclk Approximate SCL KHz 0 90 1 45 2 11 3 1 5 None None This function characterises the PC and initialise adapter ready for 12C transfers Int sendaddress int slaveaddress int setnack int slaveaddress This is the address to be accessed via the 12C e g AOH int setnack This controls whether the Parallel 12C Communications Adapter transmits an Acknowledge down the 12C Bus on reception of a byte The last byte received during a transfer must not be acknowledged in all other cases acknowledge must be enabled If setnack 0 then acknowledge is enabled if setnack 1 then acknowledge is disabled Therefore if a read odd numbered address is being sent AND only 1 Byte is to be read setnack should be set to 1 in all other cases it must be clear 0 int ErrCode lf the transfer time out occurs error code 8001H is returned otherwise the status is returned The adapter must be configured for PC and application by running setup The function waits for the bus to be free Then sends the slave address with the appropriate acknowledge The acknowledge is set ready for the data transfer after the address and hence in read mode odd address being sent if only one byte is to be read the setnack parameter must equal 1 If more than one byte is to be read or if in write mode even address being sent then setnack must equal 0 The function waits for the address to be sent Should a time out occ
28. he Control Register is accessed using the controloutp and controlinp functions The function definitions for these are as follows void controloutp int controldata int controlinp void The Data Register is accessed using the dataoutp and datainp functions The function definitions for these are as follows void dataoutp int controldata int datainp void E g in C controloutp Oxc3 would cause an Parallel 12C Communications Adapter to generate a Stop condition on the I2C bus For detailed information on these codes the Philips data sheet on the PCF8584 device see Further Information section 0x00 read write own address register followed by a data byte to the data register 0x20 read write clock register followed by a data byte to the data register After either of the above operations 0x41 must be written to the control register to re enable the 12C interface OxC3 send a Stop signal over the 12C bus 0x41 12C NOP no operation instruction acknowledge enabled Use 0x41 and 0x40 to turn on and off acknowledge 0x45 While bus is free Send Start amp slave address acknowledge enabled The address to be sent must have first been written to the data register before sending the start code 0x45 While already master on the bus Send Repeated Start amp slave address Restart The address to be sent is placed in the data register after sending the start code 0x47 Send Stop Start slave address i e
29. ite and word addresses so array allows 256 bytes of data transferarray 0 amp HAO slave write address transferarray 1 amp HOO slave word address transferarray 2 256 the number of bytes bytes_sent sendbytes transferarray 0 44 4 setup Function specification Void setup int baseaddress int ownaddress int sclk int statuswait Parameters are int baseaddress This has no function and any value may be passed to setup The baseaddress has been retained to enable applications written for the ICA90 ICA93 to be rapidly ported to the PICA93LV int ownaddress This is the 12C address to which the adapter is to respond in slave mode This forms the upper 7 bits of the 8 bit address the lowest bit being the read 1 or write 0 bit This means that if ownaddress 57H the card will respond to a write address of AEH and a read address of AFH int statuswait Issue 1 3 Page 20 22 07 99 Parameters returned Prerequisites Functional description 4 4 5 sendaddress Function specification Parameters are Parameters returned Prerequisites Functional description 4 4 6 writebyte Function specification Parameters are Issue 1 3 22 07 99 CALIBRE CALIBRE This is a period of time in micro seconds to wait for the required bus status If this time out expires the 12C functions will exit returning an error code int sclk This is the clock rate bit rate for the 12C serial bus when op
30. les Issue 1 3 Page 4 22 07 99 CALIBRE CALIBRE The I2CINC C file contains all the functions required to build an 12C transfer This will require compiling note the include file to produce an object file Once the object files have been created link them together with the library file to create your applications executable file The functions contained in I2CINC C are as detailed below Subroutine Name Brief Functional Description setup Sets user defined initial conditions getstatus Reads status register sendaddress Sends slave address data transmission mode and start signal sendstop Sends stop signal writebyte Writes a byte of data to a previously specified address readbyte Reads a byte of data from a previously specified address restart Sends Restart and slave address of device which is to be communicated with without sending a Stop Two sample programs are also supplied these examples show how the functions provided in I2CINC C are put together to provide a complete 12C transfer The sample programs are PROMREAD C Reads a number of bytes from an 12C serial EEPROM PROMWRIT C Writes a number of bytes to an I2C serial EEPROM These programs were compiled using the Zortech C compiler the make files used are supplied If you are using the Zortech C compiler copy the desired make file to MAKEFILE then type MAKE lt CR gt Editing the make files will reveal that the file I2CINC C is compiled and linked with the ap
31. nsmitted status is HEX i2cstatus else print Data has been transmitted End lf End Sub 4 3 6 Send an 12C Stop Routine Function definition Usage Function Parameters are Value Returned 12C status on exit Example Usage sendstop i2cstatus sendstop procedure to send a Stop end of communication signal down the 12C Bus sending a transmission or reception with a slave which was address previously by sendaddress None i2cstatus The value returned depends on whether the bus became free If the bus became free then the status amp H81 is returned If the bus does not became free then the last status read IORed with amp H8000 will be returned The function will read the status a number of times waiting for the bus to become free before returning an none free status this number is defined by the MAXNUMBEROFGOES constant defined in l2CINC BAS this value may be altered to suit your system The status of the Parallel 12C Communications Adapter will be amp H81 bus idle and no unread untransmitted data in data register Note this may not be the case in a system where there is another master as well as the Parallel 12C Communications Adapter since this other master may well have taken control of the bus by the time a program next uses getstatus to read the status register See Appendix A for details of status codes see also sample programs This will write a Stop to th
32. o should know be enabled again after reading the data int i2cdata The value returned depends on whether the data was read successfully If the data was read then the value is returned If the data cannot be read because there is none in the register then the last status read IORed with 0x8000 will be returned The function will read the status a number of times before returning an error condition this number is defined by the MAXNUMBEROFGOES constant defined in I2CINC C this value may be altered to suit your system 0x00 bus busy and unread data in data register 0x80 bus busy and no unread data in data register The value will depend on whether any more bytes of data have been transmitted by the slave device which is being read See Appendix A for details status codes see also sample programs This will read a byte of data from a slave previously addressed by and with acknowledge already disabled by sendaddress After reading the data acknowledge will be re enabled main int setnack i2cdata setnack 0 Enable acknowledge only one byte it to be read see parameter descriptions i2cdata readbyte setnack if i2cdata amp 0x8000 0x8000 printf Data read fault i2c status x i2cdata printf Data read was x n i2cdata Issue 1 3 22 07 99 Page 10 CALIBRE CALIBRE 4 2 5 Write Data Byte to Slave Routine Function definition int w
33. plication The makefiles are READ MAK The make file for PROMREAD C WRITE MAK The make file for PROMWRIT C If you are not using the Zortech C compiler you will have to create a similar make file see your compiler documentation for further information 3 3 DOS QBASIC Library Programs 3 3 1 Files on disc B SOURCE I2CINC BAS The I2C transfer functions B SOURCE PROMREAD BAS Sample EEPROM reading function B SOURCE PROMWRIT BAS Sample EEPROM writing function The 12C functions contained in I2CINC BAS are detailed below Subroutine Name Brief Functional Description setup Sets user defined initial conditions getstatus Reads status register sendaddress Sends slave address data transmission mode and start signal sendstop Sends stop signal writebyte Writes a byte of data to a previously specified address readbyte Reads a byte of data from a previously specified address restart Sends restart and slave address of device which is to be communicated with without sending a Stop Two sample programs are also supplied these examples show how the functions provided in I2CINC BAS are put together to provide a complete 12C transfer The sample programs are PROMREAD BAS Reads a number of bytes from an 12C serial EEPROM PROMWRIT BAS Writes a number of bytes to an I2C serial EEPROM Issue 1 3 Page 5 22 07 99 3 4 Windows LIB DLL Functions 3 4 1 Files on disc readme doc User Information win c l2cinc h C
34. r 0 int i2cstatus The value returned depends on whether the Start and address were sent If the start and address have been sent then the status returned will either be 0x00 bus busy data sent and acknowledged or 0x08 bus busy data sent but not acknowledged If the start or the address cannot be sent either the bus remained busy or the address did not get sent then the last status read IORed with 0x8000 will be returned The function will read the status a number of times before returning an error condition this number is defined by the MAXNUMBEROFGOES constant defined in I2CINC C this value may be altered to suit your system 0x00 bus busy and address sent and acknowledged 0x08 bus busy and address sent but not acknowledged 0x80 bus busy and address not sent see Appendix A for details of status codes see also sample programs main int slaveaddress setnack trash slaveaddress Oxa1 12C Address of slave this is a typical read address for an 12C static RAM or EEPROM setnack 0 Enable Acknowledge see parameter descriptions i2cstatus restart slaveaddress setnack trash readbyte setnack read the address from the adapter and discard Issue 1 3 22 07 99 Page 13 CALIBRE CALIBRE 4 3 QBASIC Routines 4 3 1 l2C Setup Initialisation Routines Function definition setup ownaddress as integer sclk as integer Usage call setup ownaddress as integer sclk as in
35. red address is being sent AND only 1 byte is to be read setnack should be set 1 in all other cases it must be clear 0 Value Returned int i2cstatus The value returned depends on whether the Start and address were sent If the start and address have been sent then the status returned will either be 0x00 bus busy data sent and acknowledged or 0x08 bus busy data sent but not acknowledged If the start or the address cannot be sent either the bus remained busy or the address did not get sent then the last status read IORed with 0x8000 will be returned Issue 1 3 Page 8 22 07 99 12C status on exit Example Usage CALIBRE CALIBRE The function will read the status a number of times before returning an error condition this number is defined by the MAXNUMBEROFGOES constant defined in I2CINC C this value may be altered to suit your system 0x00 bus busy and address sent and acknowledged 0x08 bus busy and address sent but not acknowledged 0x80 bus busy and address not sent see Appendix A for details of Status codes see also sample programs This will send a start and the 12C Slave Address of the device to be communicated with main int slaveaddress setnack i2cstatus slaveaddress Oxa0 12C Address of slave this is a typical write for an 12C static RAM or EEPROM setnack 0 Enable Acknowledge see parameter descriptions i2cstatus sendaddress slaveaddress setnack
36. ritebyte int i2cdata Usage i2cstatus writebyte i2cdata Function This is the procedure to write a byte of data to a slave device whose slave address has already been sent by sendaddress Parameters are int i2cdata The byte of data which is to be written to the slave device Value Returned The value returned depends on whether the data was written successfully If the data was written then the status is returned If the data cannot be written then the last status read ORed with 0x8000 will be returned The function will read the status a number of times before returning an error condition this number is defined by the MAXNUMBEROFGOES constant defined in I2CINC C this value may be altered to suit your system I2C status on exit 0x00 bus busy and data transmitted and acknowledged successfully 0x08 bus busy and data transmitted successfully but not acknowledged 0x80 bus busy and data not transmitted See Appendix A for details of status codes Example Usage see also sample programs This will write a byte of data to a slave previously addressed by sendaddress main int i2cdata i2cstatus i2cdata 0x69 Data byte which is to be transmitted i2cstatus writebyte i2cdata if i2cstatus amp 0x8000 0x8000 printf Data has not been transmitted status is x n i2cstatus printf Data has been transmitted n Issue 1 3 Page 11 22 07 99 CALIBRE CALIBRE 4 2 6 Send an 12C Stop
37. rosoft C These utilities can be used for setup the PICA and to perform basic communications 3 2 DOS C Library Programs 3 2 1 Files on disc C CLIB SPICA LIB The library containing the low level functions small memory model C CLIB CPICA LIB The library containing the low level functions compact memory model C CLIB MPICA LIB The library containing the low level functions medium memory model C CLIB LPICA LIB The library containing the low level functions large memory model C LIBSOURC PICA C The source code for the libraries C INC PICA H The include file for the library C SOURCE I2CINC C The I2C transfer functions C SOURCE PROMREAD C Sample EEPROM reading function C SOURCE PROMWRIT C Sample EEPROM writing function C SOURCE READ MAK Make file for PROMREAD C C SOURCE WRITE MAK Make file for PROMWRIT C 3 2 2 Typical C Project Arrangement include PICA H XPICA LIB it I2CINC C User applicat e g PROMREAD Figure 2 0 Typical Project Arrangement Figure 2 0 shows a typical C project Calibre UK Ltd have produced the library files SPICA LIB MPICA LIB CPICA LIB and LPICA LIB which contains all the low level functions required to interface to the adapter via the parallel port These libraries cover the standard memory models the library appropriate to the memory model of your project will require linking with the object fi
38. s returned Getbytes can only be used in master read mode void slavelastbyte none Adapter must be configured using setup This function would normally only be called following the end of a transmission in slave write mode when the adapter is being read as a slave by another master not when writing to a slave using the adapter This function is used when the adapter is a slave being read by a master elsewhere on the bus the adapter is in slave write mode The function must be called immediately after the master indicates the last byte has been read by not acknowledging that byte This function is required to clear the 12C data lines so that the master can send a stop signal Page 26 CALIBRE CALIBRE FURTHER INFORMATION A Philips Semiconductors Technical Handbook Book 4 Parts 12a and 12b These give details of the I2C compatible ICs and the 12C Bus specification The PCF8584P used on the adapter is included in later editions Where the data sheet and this manual disagree this manual should always be followed when using the adapter B Philips Components Data Sheet for PCF8584 C Philips Application Note No EIE AN90001 Interfacing PCF8584 12C bus controller to 80 C 51 family micro controllers This gives some useful code but is not written directly for the PC Please note the hardware information on the PCF8584 given in this application note sometimes contradicts the data sheet referenced in 8 2 in general the d
39. scriptions in this section apply equally to both C and Visual Basic applications 4 4 1 Users of ICA90 93 12C adapters For those customers who have already used the ICA90 or ICA93 I2C adapters and are wishing to convert there windows applications to the Parallel I2C Adapter the following changes will have to be made C applications Change the link option to c your path LPTI2C LIB The I2CINC H file is identical for both the ICA90 93 and the PICA93LV applications VB3 0 applications Replace the project file CALI2C BAS for the LPTI2C BAS supplied To simplify the conversion the setup function retains the base address parameter this is not used by the PICA93LV function and any integer value may be passed even your existing 310 hex 4 4 2 C functions Function Prototypes To ensure the prototypes are added correctly copy the file I2CINC H into the directory containing your project and add the line include I2CINC H Remember to add the library LPTI2C LIB to your project make file 4 4 3 Visual Basic 3 0 functions Add the file LPTI2C BAS to your project this contains the declarations for the procedures within the DLL If the DLL is not in the root directory change the path to the DLL to suit your system The sendbytes and getbytes functions pass the transfer array to the DLL by reference the following example indicates how to do this ReDim transferarray 0 to 258 remember 3 locations are required for the slave wr
40. sent AND only 1 Byte is to be read setnack should be set to 1 in all other cases it must be clear 0 Value Returned i2cstatus The value returned depends on whether the Start and address were sent If the start and address have been sent then the status returned will either be amp HOO bus busy data sent and acknowledged or amp H08 bus busy data sent but not acknowledged If the start or the address cannot be sent either the bus remained busy or the address did not get sent then the last status read IORed with amp H8000 will be returned The function will read the status a number of times before returning an error condition this number is defined by the MAXNUMBEROFGOES constant defined in I2CINC BAS this value may be altered to suit your system I2C status on exit amp HOO bus busy and address sent and acknowledged amp HO08 bus busy and address sent but not acknowledged amp H80 bus busy and address not sent see Appendix A for details of Status codes Example Usage see also sample programs Sub main slaveaddress amp HA1 12C Address this is a typical slave read address setnack 0 Enable Acknowledge see parameter descriptions i2cstatus restart slaveaddress setnack trash readbyte setnack read the address from the adapter and discard End Sub Issue 1 3 Page 19 22 07 99 CALIBRE CALIBRE 4 4 Libraries for Programming in Microsoft Windows Environments The library function de
41. st be clear 0 In the case of reading 1 byte only acknowledge will have been disabled by sendaddress and so should now be enabled again after reading the data i2cdata The value returned depends on whether the data was read successfully If the data was read then the value is returned If the data cannot be read because there is none in the register then the last status read IORed with amp H8000 will be returned The function will read the status a number of times before returning an error condition this number is defined by the MAXNUMBEROFGOES constant defined in I2CINC C this value may be altered to suit your system 0x00 bus busy and unread data in data register 0x80 bus busy and no unread data in data register The value will depend on whether any more bytes of data have been transmitted by the slave device which is being read Page 16 Example Usage CALIBRE CALIBRE See Appendix A for details status codes see also sample programs This will read a byte of data from a slave previously addressed by and with acknowledge already disabled by sendaddress After reading the data acknowledge will be re enabled Sub Main setnack 0 Enable Acknowledge only one byte is to be read see parameter descriptions i2cdata readbyte setnack if i2cdata and amp H8000 amp H8000 then print Data read fault i2c status Hex i2cdata else print Data read was Hex i2cdata en
42. switch i2cstatus case 0x00 printf Start and 12C Slave Address sent and acknowledged n case 0x08 default printf Start and 12C Slave Address sent and not acknowledged n printf Start not sent status is x i2cstatus 4 2 4 I2C Read Data Byte from Slave Routine Function definition Usage Function Issue 1 3 22 07 99 int readbyte int setnack i2cdata readbyte setnack This is the function to read a byte of data from a slave device whose slave read address has already been sent by sendaddress or restart It can be used to disable acknowledge after reading data if it is the last but one byte to be read Note First byte read after read address is always that address and should be discarded This byte should be ignored when working out when to acknowledge not acknowledge Page 9 Parameters are Value Returned 12C status on exit Example Usage CALIBRE CALIBRE int setnack This controls whether the Parallel 12C Communications Adapter transmits an Acknowledge down the I2C Bus on reception of a byte The last byte received during a transfer must not be acknowledged If setnack 0 then acknowledge is enabled if setnack 1 then acknowledge is disabled Therefore if the LAST BUT ONE byte is to be read setnack should be set to 1 in all other cases it must be clear 0 in case of reading 1 byte only acknowledge will have been disabled be sendaddress or restart and s
43. teger Function procedure to set up Parallel 12C Communications Adapter Parameters are ownaddress I2C address to which the adapter is to respond in slave mode This forms the upper 7 bits of the 8 bit address the lowest bit being the Read 1 or Write 0 bit This means that if ownaddress amp h57 the card will respond to a Write to address amp hAF Be sure not to select an address which is already in use by any other device in your 12C system If ownaddress amp h00 the adapter will monitor all I2C bus information but will not affect any data transfers thus acting as a bus monitor sclk the SCL clock rate bit rate for 12C serial bus Value of sclk Approximate SCL KHz 0 90 1 45 2 11 3 1 5 Value Returned none 12C status on exit 12C status on exit from routine the Parallel 12C Communications Adapter will have the serial interface enabled also data reception acknowledge will be enabled The status register will contain 0x81 assuming that no other masters exist on the I2C system if this is not the case then the contents of the status register will also depend on externally generated bus activity Example Usage see also sample programs This will set up the Parallel 12C Communications Adapter with an I2C slave address of amp HAE anda SCL clock rate of approximately 45KHz sub main ownaddress amp h57 Own slave address set to amp h57 hex sclk 1 Serial clock rate set to 45KHz call setup ownaddress
44. unications Adapter transmits an Acknowledge down the 12C Bus on reception of a byte The last byte received during a transfer must not be acknowledged in all other cases acknowledge must be enabled If setnack 0 then acknowledge is enabled if setnack 1 then acknowledge is disabled Therefore if a read odd numbered address is being sent AND only 1 byte is to be read setnack should be set to 1 in all other cases it must be clear 0 Value Returned l2cstatus The value returned depends on whether the Start and address were sent If the start and address have been sent then the status returned will either be amp HOO bus busy data sent and acknowledged or 0x08 bus busy data sent but not acknowledged If the start or the address cannot be sent either the bus remained busy or the address did not get sent then the last status read IORed with amp H8000 will be returned The function will read the status a number of times before returning an error condition this number is defined by the MAXNUMBEROFGOES constant defined in I2ZCINC BAS this value may be altered to suit your system I2C status on exit amp HOO bus busy and address sent and acknowledged amp HO08 bus busy and address sent but not acknowledged amp H80 bus busy and address not sent see Appendix A for details of Status codes Example Usage see also sample programs This will send a Start and the 12C Slave Address of the device to be communicated with Issue
45. ur during the sending of an address then an error code 8001H is returned otherwise the status is returned Int writebyte int wrData int wrData This is the byte of data to be written Page 21 Parameters returned Prerequisites Functional description 4 4 7 readbyte Function specification Parameters are Parameters returned Prerequisites Functional description 4 4 8 sendstop Function specification Parameters are Parameters returned Prerequisites Functional description Issue 1 3 22 07 99 CALIBRE CALIBRE int ErrCode lf the transfer time out occurs error code 8004H is returned otherwise the status is returned Adapter must be configured using setup start and write address sent by sendaddress The function writes the data to the adapter and then waits for it to be sent Should a time out occur during the sending of the data then error code 8004H is returned otherwise the status is returned Writebyte is compatible with both master write and slave write modes Int readbyte int setnack int setnack This controls whether the Parallel 12C Communications Adapter transmits an Acknowledge down the 12C Bus on reception of a byte The last byte received during a transfer must not be acknowledged in all other cases acknowledge must be enabled If setnack 0 then acknowledge is enabled if setnack 1 then acknowledge is disabled Therefore if a read odd numbered address is being sent AND
46. ware you are running 5 The serial number of your 12C adapter or when you purchased it PLEASE EMAIL YOUR QUERY TO echsupport calibreuk com OR FAX YOUR QUERY TO 44 1274 730960 We will endeavour to help you Issue 1 3 22 07 99 Page 32
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