DM5804/DM6804 User`s Manual
Contents
1. OUT CR amp HB POINT TO COUNTER 3 LOAD REGISTER TABLE 5 1 OUT DR amp H0 COUNTER 3 LSB OUT DR amp H0 COUNTER 3 MSB OUT CR amp H67 LOAD amp ARM COUNTERS 1 2 amp 3 TABLE 5 2 The main program is OUT CR amp HA4 SAVE COUNTER 3 IN HOLD REGISTER TABLE 5 2 OUT CR amp H13 POINT TO COUNTER 3 HOLD REGISTER TABLE 5 1 LSB INP DR READ COUNTER 3 LSB MSB INP DR READ COUNTER 3 MSB RESULT LSB MSB 256 COMBINE LSB amp MSB LOCATE 12 37 PRINT USING RESULT ON KEY 1 GOSUB QUIT GOTO MAIN To quit KEY 1 OFF END 5 8 F1 F2 F3 F4 F5 EXAMPLE Setting Up the Am9513A as a Frequency Counter This program FCOUNT on the example disk shows you how to program the Am9513A as a simple frequency counter In this example counter 4 is used to divide the on board 5 MHz clock by 10 000 The output from counter 4 5 MHz 10 000 500 Hz is used to clock counter 5 Counter 5 is used to divide this 500 Hz clock by 500 The result is a 1 Hz output which is used to gate counter 1 This 1 Hz output is also used to trigger the interrupt status bit The program monitors this status bit to determine when to read counters and 2 Counters 1 and 2 are used to count the SRCI input for 1 second intervals NOTE For this program to operate properly a jumpe2. OD DE BO CIC OS DS Se 9 G9 E Ie dd CIO UE Oe GITAL GND GITAL GND GITAL GND 5 VOLTS DIGITAL GND Fig 2 1 P2 I O Connector Pin Assignments Connecting the Timer Counters and Digital I O For all of the digital connections the high side of an external signal source or destination device is connected to the appropriate signal pin on the I O connector and the low side is connected to any DIGITAL GND Running the 5804DIAG Diagnostics Program Now that your board is ready to use you will want to try it out An easy to use menu driven diagnostics program 5804DIAG is included with your example software to help you verify your board s operation You can also use this program to make sure that your current base address setting does not contend with another device 2 4 CHAPTER 3 HARDWARE DESCRIPTION This chapter describes the features of the DM5804 hardware The major circuits are the timer counters and the digital I O lines This chapter also describes the hardware selectable interrupts 3 1 3 2 The DM5804 has two major circuits the timer counters and the digital I O lines Figure 3 1 shows the block diagram of the board This chapter describes the hardware which makes up the major circuits and hardware selectable interrupts DIGITAL I O ADDRESS DECODE PULL UP DOWN RESISTORS INTERRUPT PC BUS 1 0 CONNECTOR SELECT DATA CONTROL 5 VOLTS DIGITAL GROUND Fig 3 1 D
3. Output capacitance C OUT lt F 1ME2Z_ u ua an ahnen 20 pF Timer Couriter lille ica did Am9513A Five 16 bit timer counters Binary or BCD up or down counting Programmable operating modes eene 24 Counter input source ii External clock 6 9 MHz max on board 5 MHz clock external gate input or adjacent counter output Counter outputs s oues BASSES Pen Available externally used as PC interrupts or internally cascaded to adjacent counter Counter gate SOUFCE ii External input counter output or software control Miscellaneous Inputs Outputs 5 volts digital ground PC bus sourced External interrupt input Frequency output Additional gate inputs Current Requirements 5 VOS nali los us ee ario on end 220 mA max P2 Connector 50 pin right angle header Size 3 55 L x 3 775 W x 0 6 H 90mm x 96mm x 16mm A 3 A 4 APPENDIX B P2 CONNECTOR PIN ASSIGNMENTS B 1 B 2 srct OQO Gare our our GATE sRc2 src3 O GATE3 our4 OUT3 GATE4 1003 sRc4 sRcs 13 GATES DIGITAL GND 15 OUTS EXTINT G2G8 DIGITAL GND PIN 1 FOUT DIGITAL GND DIGITAL GND 2 62 DIGITAL GND PA7 3 PC7 i PA6 5 PC6 i PAS PCS PA4 PC4 Pas GI Pos f PA2 63 PC2 Par 6 PCI Pao PCO PB7 PB6 PB5 PB4 PB3 PB2 PB1 PB0 12 VOLTS d 5 VOLTS PIN 49 12 VOLTS DIGITAL GND P2 Mating Connector Part Numbers Manufacturer Part Number
4. you may want to pull down lines connected to relays which control turning motors on and off These motors turn on when the digital lines controlling them are high To use the pull up pull down feature you must first install 10 kilohm resistor packs in any or all of the four locations around the 8255 labeled PA PB PCL and PCH PA and PB take 10 pin packs and CL and CH take 6 pin packs Figure 1 6 shows a blowup of PA and PB o she peres K en to put Fig 1 6 Port A and Port B Pull up Pull down Resistor Circuitry After the resistor packs are installed you must connect them into the circuit as pull ups or pull downs Locate the three hole pads on the board near the resistor packs They are labeled G for ground on one end and V for Vcc on the other end The middle hole is common PA is for Port A PB for Port B CL is for Port C Lower and CH is for Port C Upper Figure 1 6 shows a blowup of the pads for Port A and Port B To operate as pull ups solder a jumper wire between the common pin middle pin of the three and the V pin For pull downs solder a jumper wire between the common pin middle pin and the G pin For example Figure 1 7 shows Port A lines with pull ups Port C Lower with pull downs and Port C Upper with no resistors Fig 1 7 Adding Pull ups and Pull downs to Some Digital I O Lines 1 7 CHAPTER 2 BOARD INSTALLATION The DM5804 is easy to install in your cpuModule or o
5. 1 746094 0 3425 7650 B 3 B 4 C 1 APPENDIX C COMPONENT DATA SHEETS AMD Am9513A System Timing Controller Data Sheet Reprint Intel 82C55A Programmable Peripheral Interface Data Sheet Reprint APPENDIX D WARRANTY D 2 LIMITED WARRANTY Real Time Devices Inc warrants the hardware and software products it manufactures and produces to be free from defects in materials and workmanship for one year following the date of shipment from REAL TIME DE VICES This warranty is limited to the original purchaser of product and is not transferable During the one year warranty period REAL TIME DEVICES will repair or replace at its option any defective products or parts at no additional charge provided that the product is returned shipping prepaid to REAL TIME DEVICES All replaced parts and products become the property of REAL TIME DEVICES Before returning any product for repair customers are required to contact the factory for an RMA number THIS LIMITED WARRANTY DOES NOT EXTEND TO ANY PRODUCTS WHICH HA VE BEEN DAM AGED AS A RESULT OF ACCIDENT MISUSE ABUSE such as use of incorrect input voltages improper or insufficient ventilation failure to follow the operating instructions that are provided by REAL TIME DEVICES acts of God or other contingencies beyond the control of REAL TIME DEVICES OR AS A RESULT OF SERVICE OR MODIFICATION BY ANYONE OTHER THAN REAL TIME DEVICES EXCEPT AS EX PRESSLY SET FORTH ABOVE NO OT
6. 5 BA 6 IRO Enable Write Only eco E tq oet o e ec eR eher ee 4 6 BA 7 Interrupt Status Clear Read Write iii 4 6 Programming the DM5804 x ep esI e hr HI RE RN DIR RR IR wen dde 4 7 Clearing and Setting Bits in a Port ntes 25820002 Kessel ei RD esta 4 8 Initializing the AMISISA nins Sich ick aa np EH e RO te e t i sis 4 0 Initializing the 8255 AA ed e OR REEF EC ERROR EVER Tete Cr d 4 0 Digital DO Operations 52 laicale ia ERR E IER EE 4 9 Interr pts 5n ate tee de Bo E BRE e e EE te BIN ROO dae aan es 4 10 What Is an Interrupt a eeii i e Rte the e oo editos e e ette XR te hend 4 10 Interr pt RequestIinesS eene i tete ep te dete eO HG their 4 10 8259 Programmable Interrupt Controller essere nennen eene nennen trennen 4 10 Interrupt Mask Register IMR rre eo e ss ini HER sp 4 10 End of Interrupt EOD Command i 4 10 What Exactly Happens When an Interrupt Occurs eene enne nrenenn nee 4 11 Using Interrupts in Your Programs esie tee tete tt re RD aes o 4 11 Writing an Interrupt Service Routine ISR i 4 11 Saving the Startup Interrupt Mask Register IMR and Interrupt Vector sese 4 12 Restoring the Startup IMR and Interrupt Vector nennen nennen erre nenne 4 13 Common Interrupt Mistakes tute ep get de it ere e ERR erts 4 13 Example Programs rem rr NGHE EE AN IE ERE E PEE G
7. PPI operating modes Mode 0 Basic input output Lets you use simple input and output operation for a port Data is written to or read from the specified port Mode 1 Strobed input output Lets you transfer I O data from Port A or Port B in conjunction with strobes or handshaking signals Mode 2 Strobed bidirectional input output Lets you communicate bidirectionally with an external device through Port A Handshaking is similar to Mode 1 These modes are detailed in the 8255 Data Sheet reprinted from Intel in Appendix C Interrupts The DM5804 has four jumper selectable interrupt sources PC3 which is the INTRA signal from the 8255 PPI PCO which is the INTRB signal from the 8255 PPI OUTS the output from Am9513A timer counter 5 and EXTINT an external interrupt you can route onto the board through I O connector P2 Chapter 1 tells you how to set the jumpers on the interrupt header connectors P3 and P4 and Chapter 4 describes how to program interrupts 3 4 CHAPTER 4 BOARD OPERATION AND PROGRAMMING This chapter shows you how to program your DM5804 It provides a complete description of the I O map and a description of programming operations to aid you in programming The example programs included on the disk in your board package are listed at the end of this chapter These programs written in Turbo C Turbo Pascal and BASIC include source code to simplify your applications programming Chapter 5 contains examples
8. Pascal examples show what the shell of your ISR should be like In C void interrupt ISR void Your code goes here Do not use any DOS functions outportb BaseAddress 7 0 Clear DM5804 interrupt outportb 0x20 0x20 Send EOI command to 8259 In Pascal Procedure ISR Interrupt begin Your code goes here Do not use any DOS functions Port BaseAddress 7 0 Clear DM5804 interrupt Port 20 20 Send EOI command to 8259 end Saving the Startup Interrupt Mask Register IMR and Interrupt Vector The next step after writing the ISR is to save the startup state of the interrupt mask register and the interrupt vector that you will be using The IMR is located at I O port 21H The interrupt vector you will be using is located in the interrupt vector table which is simply an array of 256 bit 4 byte pointers and is located in the first 1024 bytes of memory Segment 0 Offset 0 You can read this value directly but it is a better practice to use DOS function 35H get interrupt vector Most C and Pascal compilers provide a library routine for reading the value of a vector The vectors for the hardware interrupts are vectors 8 through 15 where IRQO uses vector 8 IRQ1 uses vector 9 and so on Thus if the DM5804 will be using IRQ3 you should save the value of interrupt vector 11 Before you install your ISR temporarily mask out the IRQ you will be using This prevents the IR
9. To connect an interrupt source place the jumper across the desired set of pins Note that only ONE interrupt source can be activated at a time PC3 PCO OUT5 EXTINT P4 Fig 1 4 Interrupt Source Select Jumper P4 S1 Base Address Factory Setting 300 hex 768 decimal One of the most common causes of failure when you are first trying your board is address contention Some of your computer s I O space is already occupied by internal I O and other peripherals When the DM5804 board attempts to use I O address locations already used by another device contention results and the board does not work To avoid this problem the DM5804 has an easily accessible DIP switch S1 which lets you select any one of 64 starting addresses in the computer s I O Should the factory setting of 300 hex 768 decimal be unsuitable for your system you can select a different base address simply by setting the switches to any value shown in Table 1 2 The table shows the switch settings and their corresponding decimal and hexadecimal in parentheses values Make sure that you verify the order of the switch numbers on the switch 1 through 6 before setting them When the switches are pulled forward they are OPEN or set to logic 1 as labeled on the DIP switch package When you set the base address for your board record the value in the table inside the back cover Figure 1 5 shows the DIP switch set for a base address of 300 hex 768 decimal Table 1
10. for setting up the timer counters for specific applications 41 4 2 Defining the VO Map The I O map for the DM5804 is shown in Table 4 1 below As shown the board occupies eight consecutive I O port locations The base address designated as BA can be selected using DIP switch S1 as described in Chapter 1 Board Settings This switch can be accessed without removing the board from the connector The following sections describe the register contents of each address used in the I O map Register Description Read Function Decimal boss PI o A ReadPon A digtatinput imes jm Soa OPA 8255 PPI Port A Read Port A digital input lines lines BA 0 poss PI Pa e Read Pont B aigtatinput imes fe 8255 PPI Port B Read Port B digital input lines lines BA 1 poss PI an Read Pont again fe o OPA 8255 PPI Port C Read Port C digital input lines lines BA 2 BA 9 BA 4 BA 5 Enable and disable interrupt Reserved generation BA 6 Read status of interrupt Clear interrupt BA 7 BA 0 PPI Port A Digital I O Read Write Transfers the 8 bit Port A digital input and digital output data between the board and an external device A read transfers data from the external device through P2 and into PPI Port A a write transfers the written data from Port A through P2 to an external device BA 1 PPI Port B Digital I O Read Write Transfers the 8 bit Port B digital input and digital output data between the board and an external device A
11. is driven high by a peripheral device such as the DM5804 the interrupt controller checks to see if interrupts are enabled for that IRQ and then checks to see if other interrupts are active or requested and determines which interrupt has priority The interrupt controller then interrupts the proces sor The current code segment CS instruction pointer IP and flags are pushed on the stack for storage and a new CS and IP are loaded from a table that exists in the lowest 1024 bytes of memory This table is referred to as the interrupt vector table and each entry is called an interrupt vector Once the new CS and IP are loaded from the interrupt vector table the processor begins executing the code located at CS IP When the interrupt routine is completed the CS IP and flags that were pushed on the stack when the interrupt occurred are now popped from the stack and execution resumes from the point where it was interrupted Using Interrupts in Your Programs Adding interrupts to your software is not as difficult as it may seem and what they add in terms of performance is often worth the effort Note however that although it is not that hard to use interrupts the smallest mistake will often lead to a system hang that requires a reboot This can be both frustrating and time consuming But after a few tries you ll get the bugs worked out and enjoy the benefits of properly executed interrupts In addition to reading the following paragraphs stud
12. read transfers data from the external device through P2 and into PPI Port B a write transfers the written data from Port B through P2 to an external device BA 2 PPI Port C Digital I O Read Write Transfers the two 4 bit Port C digital input and digital output data groups Port C Upper and Port C Lower between the board and an external device A read transfers data from the external device through P2 and into PPI Port C a write transfers the written data from Port C through P2 to an external device 43 BA 3 8255 PPI Control Word Write Only When bit 7 of this word is set to 1 a write programs the PPI configuration The table below shows the control words for the 16 possible Mode 0 Port I O combinations Mode Set FI eli eo 3 oge DE ag Port C Lower 1 active l 0 output Mode Select 1 input 00 mode0 01 mode 1 Port B mode output 10 mode 2 0 1 input Port A I 0 output Mode Select 1 input 0 mode 0 1 mode 1 gt 4 4 When bit 7 of this word is set to 0 a write can be used to individually program the Port C lines D7 D6 D5 D4 D3 D2 DI DO Set Reset Bit Set Reset Function Bit Bit Select 0 setbitto 0 0 active 000 PCO 1 set bit to 1 001 PC1 010 PC2 011 PC3 100 PC4 101 PC5 110 PC6 111 PC7 For example if you want to set Port C bit 0 to 1 you would
13. 1 5 Pull up Pull down Resistors on Digital VO Lines essere nennen nennen nennen nene nrennen 1 6 CHAPTER 2 BOARD INSTALLATION in uwi nese rio seasons tasa ee netsoos 2 1 Board Installation iris 2 3 External VO CONNECTIONS Wii 2 3 Connecting the Timer Counters and Digital I O nono cnn ncnn cnn crono no non nooo non en nooo nennen 2 4 Running the 5804DIAG Diagnostics Program nono non crono nn crono on non rennen nente en recono trennen entree 2 4 CHAPTER 3 HARDWARE DESCRIPTION 3 1 Am9513A Timer Counters semi alari alain pite ge 3 3 Digital I O Programmable Peripheral Interface eene ener nennen ether 3 3 Inti ld a 3 4 CHAPTER 4 BOARD OPERATION AND PROGRAMMING 4 1 Defining the J O Map etus Ea eene etiem iei doeet tete 4 3 BA 0 PPI Port A Digital I O Read Write i 4 3 BA 1 PPI Port B Digital I O Read Write i 4 3 BA 2 PPI Port C Digital VO Read Write n 4 3 BA 3 8254 PPI Control Word Write Only i 4 4 BA 4 Am9513A Data Register Read Write enne eene nente ennt en netter nennen nene 4 5 BA 5 Am9513A Command Register Read Write i 4
14. 10 decimal 10 000 in counter 4 load register OUT CR amp HC POINT TO COUNTER 4 LOAD REGISTER TABLE 5 1 OUT DR amp H10 COUNTER 4 LSB OUT DR amp H27 COUNTER 4 MSB Next set up the counter 5 mode register see Figure 5 2 These are the settings we will use Gating Control no gating Source Edge rising edge Count Source Selection TCN 1 Count Control disable special gate reload from load count repetitively binary count count down Output Control TC toggled VALUE HEX 0022 OUT CR amp H5 POI TO COUNTER 5 MODE REGISTER TABLE 5 1 OUT DR amp H22 COUNTER 5 MODE LSB OUT DR amp HO COUNTER 5 MODE MSB Put the hex number 1F4 decimal 500 in counter 5 load register OUT CR amp HD POINT TO COUNTER 5 LOAD REGISTER TABLE 5 1 OUT DR amp HF4 COUNTER 5 LSB OUT DR amp H1 COUNTER 5 MSB OUT IRQCLR 0 CLEAR INTERRUPT STATUS OUT CR amp H7B LOAD amp ARM COUNTERS 1 2 4 amp 5 TABLE 5 2 The main program is IRQ INP STAT AND 1 IF IRQ lt gt 1 GOTO MAIN OUT IROCLR 0 OUT CR amp H83 OUT CR amp H63 OUT CR amp H11 LSB 1 INP DR MSB 1 INP DR LSB 2 INP DR DR MSB 2 INP ESULT LSB 1 MSB 1 256 OCA O tg td La DW N KI GOTO RINT USING RI RI
15. 2 Base Address Switch Settings S1 Base Base Base Base Address Switch Address Switch Address Switch Address Switch Decimal Setting Decimal Setting Decimal Setting Decimal Setting Hex 654321 Hex 654321 Hex 654321 Hex 560 030 000110 688 080 10110 816 330 100110 944 380 11 01000 co 11000 832 640 1 1000 3C0 01001 mac 308 50 DO 50 58 D8 58 60 E0 60 68 E8 68 70 0 70 78 8 78 o1011 zeo hoiloir esoresey 101023 s De 01100 zero oss100 sag 101 x cuyes oorror mie onszon sies 101101 men 111101 sm oor110 mesero Poirrr0 worm roriio woseo 111110 sam ooriia wore poirrrr er 101111 so 221110 0 closed 1 open 2 2 3 2 2 3 2 2 3 2 2 3 01010 ojo Poiror0 aa fioi 300 2 2 3 2 2 3 2 2 3 1 5 Fig 1 5 Base Address Switch S1 Pull up Pull down Resistors on Digital I O Lines The 8255 programmable peripheral interface provides 24 parallel TTL CMOS compatible digital I O lines which can be interfaced with external devices The lines are divided into four groups eight Port A lines four Port C Lower lines eight Port B lines and four Port C Upper lines You can install and connect pull up or pull down resistors for any or all of these four groups of lines You may want to pull lines up for connection to switches This will pull the line high when the switch is disconnected Or
16. BA 7 ADDRESS TO CLEAR INTERRUPT STATUS BIT Next you must enable status generation OUT IROEN 1 Now reset the Am9513A timer counter chip see Table 5 2 OUT CR amp HFF AM9513A MASTER RESET Next set up the Am9513A master mode register see Figure 5 1 These are the settings we will use Scaler Control binary division Data Pointer Control enable increment Data Bus Width 8 bits FOUT Gate FOUT on FOUT Divider divide by 16 FOUT Source Fl see Figure 5 3 Compare 2 Enable disabled Compare 1 Enable disabled Time of Day Mode disabled VALUE HEX 0000 OUT CR amp H17 POINT TO MASTER MODE REGISTER TABLE 5 1 OUT DR amp H0 MASTER MODE LSB OUT DR amp HO MASTER MODE MSB Next set up the counter 1 mode register see Figure 5 2 These are the settings we will use Gating Control active low gate n Source Edge rising edge Count Source Selection SRC1 Count Control disable special gate reload from load count repetitively binary count count up Output Control active high TC VALUE HEX A129 OUT CR amp Hl POI TO COUNTER 1 MODE REGISTER TABLE 5 1 OUT DR amp H29 COUNTER 1 MODE LSB OUT DR amp HA1 COUNTER 1 MODE MSB Put the hex number 0000 decimal 0 in counter 1 load registe
17. DMS5804 DM6804 User s Manual D O Real Time Devices USA Inc je EEE reo Accessing the Analog World Publication No 5804 6 18 99 DM5804 DM6804 w User s Manual GT REAL TIME DEVICES USA INC Post Office Box 906 State College Pennsylvania 16804 Phone 814 234 8087 FAX 814 234 5218 Published by Real Time Devices USA Inc P O Box 906 State College PA 16804 Copyright 1992 by Real Time Devices Inc All rights reserved Printed in U S A Table of Contents INTRODUCTION 2 i 1 A9513A Timer COoUunter 1 au amuyu m e et DI OE AIO Ue ete RE B Aia i 3 Digital IO ARL all aL We en toe o deer iet Rn i 3 What Comes With Y out B6ard y ede E eem eie e eto ute ss i 3 Board ACCeSSOTIES 4 oct ta ER EUER FERE Es RHET RE un AREE ERR ERE REUS ee AERE EYES vA i 3 Using This Manual sicario iaia rto AP Rem e RI APR nn A RR Bere i 3 When You Need Help ssi ccc ee rt e et Oo e eter RD O aA Eo neo eo Rsa i 4 CHAPTER 1 BOARDSETETINGS M n a SG scene ninna ce 2002002000000 een zione nice senses sous 1 1 Factory Configured Switch and Jumper Settings esses neret nennen rennen 1 3 P3 Interrupt Channel Select Factory Setting G Connected Interrupt Channels Disabled 1 4 P4 Interrupt Source Select Factory Setting EXTINT eese nenne nennen nenne 1 4 S1 Base Address Factory Setting 300 hex 768 decimal essere
18. ENERE Rer Qe p e nie 4 14 C and Pascal Programs tt ete ete to ore ete te aa inabili 4 14 BASIC Programs acia LIVES ALGA IAA LAI i RII eH i 4 14 CHAPTER 5 EXAMPLES OF Am9513A APPLICATIONS 5 1 EXAMPLE Counting Program Using Timer Counters 1 2 and 3 sese 5 3 EXAMPLE Setting Up the Am9513A as a Frequency Counter i 5 8 APPENDIX A DM5804 SPECIFICATIONS A 1 APPENDIX B P2 CONNECTOR PIN ASSIGNMENIT S B 1 APPENDIX C COMPONENT DATA SHEETS C 1 APPENDIX D WARRANTY essen ee an EYES PRSE svocnsseconnsessesvescuecsea D 1 1 1 1 2 1 3 1 5 1 6 1 7 2 1 3 1 5 1 5 2 5 3 List of Illustrations Board Layout Showing Factory Configured Settings ii 1 3 Interrupt Channel Select Jumper P3 ne ia oett iaia 1 4 Pulling Down the Interrupt Request Line nuna 1 4 Interrupt Source Select Jumper PA na S nennen ha trennen treten trennen 1 5 Base Address Switch ST iie datare aan 1 6 Port A and Port B Pull up Pull down Resistor Circuitry ii 1 6 Adding Pull ups and Pull downs to Some Digital I O Lines cee ceseeseceseeeeceeeeeeceeeeeesenee
19. HER WARRANTIES ARE EXPRESSED OR IMPLIED INCLUDING BUT NOT LIMITED TO ANY IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE AND REAL TIME DEVICES EXPRESSLY DISCLAIMS ALL WARRANTIES NOT STATED HEREIN ALL IMPLIED WARRANTIES INCLUDING IMPLIED WARRANTIES FOR MECHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE LIMITED TO THE DURATION OF THIS WARRANTY IN THE EVENT THE PRODUCT IS NOT FREE FROM DEFECTS AS WARRANTED ABOVE THE PURCHASER S SOLE REMEDY SHALL BE REPAIR OR REPLACEMENT AS PROVIDED ABOVE UNDER NO CIRCUMSTANCES WILL REAL TIME DEVICES BE LIABLE TO THE PURCHASER OR ANY USER FOR ANY DAMAGES INCLUDING ANY INCIDENTAL OR CONSEQUENTIAL DAM AGES EXPENSES LOST PROFITS LOST SAVINGS OR OTHER DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE PRODUCT SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF INCIDENTAL OR CONSE QUENTIAL DAMAGES FOR CONSUMER PRODUCTS AND SOME STATES DO NOT ALLOW LIMITA TIONS ON HOW LONG AN IMPLIED WARRANTY LASTS SO THE ABOVE LIMITATIONS OR EXCLU SIONS MAY NOT APPLY TO YOU THIS WARRANTY GIVES YOU SPECIFIC LEGAL RIGHTS AND YOU MAY ALSO HAVE OTHER RIGHTS WHICH VARY FROM STATE TO STATE D 3 DM5804 Board User Selected Settings Base I O Address hex decimal IRQ Channel Selected Select ONE Interrupt Source P4 C3 IRQ Channel CO IRQ Channel IRQ Channel IRQ Channel
20. IC this is programmed as V INP PortAddress V V AND 223 OUT PortAddress V To set a single bit in a port OR the current value of the port with the value b where b 2 Example Set bit 3 in a port Read in the current value of the port OR it with 8 8 25 and then write the resulting value to the port In Pascal this is programmed as V Port PortAddress V s VOR 8 Port PortAddress V Setting or clearing more than one bit at a time is accomplished just as easily To clear multiple bits in a port AND the current value of the port with the value b where b 255 the sum of the values of the bits to be cleared Note that the bits do not have to be consecutive Example Clear bits 2 4 and 6 in a port Read in the current value of the port AND it with 171 171 255 2 2 2 and then write the resulting value to the port In C this is programmed as v inportb port address V v amp 171 outportb port_address v To set multiple bits in a port OR the current value of the port with the value b where b the sum of the individual bits to be set Note that the bits to be set do not have to be consecutive Example Set bits 3 5 and 7 in a port Read in the current value of the port OR it with 168 168 2 25 2 and then write the resulting value back to the port In assembly language this is programmed as mov dx PortAddress in al dx or al 168 out dx al Often assigni
21. M804 Block Diagram Am9513A Timer Counters The Am9513A System Timing Controller contains five general purpose 16 bit timer counters which are capable of performing many different types of counting sequencing and timing functions The Am9513A supports up or down counting in binary or BCD with hardware or software gating of each counter Its 24 modes of operation are detailed in the Am9513A Data Sheet reprint from AMD included in Appendix C The Am9513A is structured with a series of internal registers that set the mode of operation for each counter These registers are fully described in Appendix C Any of the counters can be internally cascaded to create a counter of up to 80 bits For example two cascaded counters form a 32 bit counter for longer counting capability Rarely is it practical to cascade more than three counters Cascading is described in Appendix C Chapter 3 of the Am9513A data sheet The timer counters are driven by an on board 5 MHz crystal oscillator Digital I O Programmable Peripheral Interface The programmable peripheral interface PPI is used for digital I O functions This high performance TTL CMOS compatible chip has 24 digital I O lines divided into two groups of 12 lines each Group A Port A 8 lines and Port C Upper 4 lines Group B Port B 8 lines and Port C Lower 4 lines 3 3 All three ports A B and C are available at the I O connector P2 You can use these ports in one of these three
22. NT Hz GI E12 35 Y 1 GOSUB QUIT IAIN Torquit A 8 lt Ej 1 OFF ESULT CHECK IF INTERRUPT STATUS 1 CLEAR INTERRUPT STATUS DISARM amp SAVE COUNTERS 1 amp 2 TABLE 5 2 LOAD amp ARM COUNTERS 1 amp 2 TABLE 5 2 POINT TO COUNTER 1 HOLD REGISTER TABLE 5 1 READ COUNTER 1 LSB READ COUNTER 1 MSB READ COUNTER 2 LSB READ COUNTER 2 MSB LSB 2 256 2 MSB 2 256 3 5 12 APPENDIX A DM5804 DM6804 SPECIFICATIONS A 2 DM5804 DM6804 Characteristics Typical 25 C Interface cpuModule amp other PC 104 form factor compatible Switch selectable base address I O mapped Jumper selectable interrupts Digital Qu u lll ILC CMOS 82C55 Optional NMOS 8255 N rmberof4ines te st tua eric dire en u ma LN 24 Logic compalibililyzu u u aaa ie TTL CMOS Configurable with optional I O pull up pull down resistors High level output voltage aaasasd sasssa rca 4 2V min Low level output voltage i 0 45V max High level input voltage 2 2V min 5 5V max Low level input voltage ne 0 3V min 0 8V max Input load Current sone ete ee Re qas ha tei te een 10 pA Input capacitance C IN F 1MHZ_ 22_ aaa a eerte eei eiie e i 10 pF
23. Q from requesting an interrupt while you are installing and initializing your ISR To mask the IRQ read in the current IMR at I O port 21H and set the bit that corresponds to your IRQ remember setting a bit disables interrupts on that IRQ while clearing a bit enables them The IMR is arranged so that bit O is for IRQ0 bit 1 is for IRQ1 and so on See the paragraph entitled Interrupt Mask Register IMR earlier in this chapter for help in determining your IRQ s bit After setting the bit write the new value to I O port 21H 4 12 With the startup IMR saved and the interrupts on your IRQ temporarily disabled you can assign the interrupt vector to point to your ISR Again you can overwrite the appropriate entry in the vector table with a direct memory write but this is a bad practice Instead use either DOS function 25H set interrupt vector or if your compiler provides it the library routine for setting an interrupt vector Remember that vector 8 is for IRQO vector 9 is for IRQI and so on If you need to program the source of your interrupts do that next For example if you are using the program mable interval timer to generate interrupts you must program it to run in the proper mode and at the proper rate Finally clear the bit in the IMR for the IRQ you are using This enables interrupts on the IRQ Restoring the Startup IMR and Interrupt Vector Before exiting your program you must restore the interrupt mask register and
24. TER MODE LSB OUT DR amp H40 MASTER MODE MSB Next set up the counter 1 mode register see Figure 5 2 These are the settings we will use Gating Control no gating Source Edge rising edge Count Source Selection F1 Count Control disable special gate reload from load count repetitively binary count count down Output Control TC toggled VALUE HEX 0B22 OUT CR amp H1 POINT TO COUNTER 1 MODE REGISTER TABLE 5 1 OUT DR amp H22 COUNTER 1 MODE LSB OUT DR amp HOB COUNTER 1 MODE MSB 5 4 Table 5 2 Am9513A Command Summary Command Code C4 C3 C2 Command Description Load data pointer register with contents of E amp G fields E 000 G 110 E amp G fields described in Appendix C Arm counting for all selected counters Load contents of specified source into all selected counters Load amp arm all selected counters Disarm amp save all selected counters Save all selected counters in hold register Disarm all selected counters Set toggle out high for counter N 001 2 N 2 101 Clear toggle out low for counter N 001 2 N 2 101 Step counter N 001 2 N 2 101 Set MM14 disable data pointer sequencing Set MM12 gate off FOUT Set MM13 enter 16 bit bus mode Clear MM14 enable data pointer sequencing Clear MM12 gate on FOUT Clear MM13 enter 8 b
25. Time of Day Mode 00 TOD disabled FOUT Source 0000 F1 0001 SRC 1 0010 SRC 2 0011 2 SRC 3 0100 SRC 4 0101 SRC 5 0110 GATE 1 0111 GATE 2 1000 GATE 3 1001 GATE 4 1010 GATE 5 1011 F1 1100 F2 1101 F3 1110 F4 1111 F5 01 TOD enabled 5 input 10 TOD enabled 6 input 11 TOD enabled 10 input Fig 5 1 Master Mode Register Bit Assignments 5 6 OUT CR amp H2 POINT TO COUNTER 2 MODE REGISTER TABLE OUT DR amp H22 COUNTER 2 MODE LSB OUT DR amp H0 COUNTER 2 MODE MSB Put the hex number 1F4 decimal 500 in counter 2 load register OUT CR amp HA POINT TO COUNTER 2 LOAD REGISTER TABLE OUT DR amp HF4 COUNTER 2 LSB OUT DR amp H1 COUNTER 2 MSB 5 1 5 1 Count Source Selection Counter Control 0000 TCN 1 0 disable special gate 0001 SRC 1 1 enable special gate 0010 SRC 2 0011 SRC 3 0 reload from load 0100 SRC 4 1 reload from load or 0101 SRC 5 hold 0110 GATE 1 except in mode X 0111 GATE 2 which reloads only 1000 GATE 3 from load 1001 GATE 4 1010 GATE 5 0 count once 1011 F1 1 count repetitively 1100 F2 1101 F3 0 binary count 1110 F4 1 BCD count 1111 F5 0 count down 1 count up Source Edge 0 count on rising edge 1 count on falling edge Output Contr
26. by the system timer IRQ is used by the key board IRQ3 by COM2 IRQ4 by COMI and IRQ6 by the disk drives Therefore it is important for you to know which IRQ lines are available in your system for use by the DM5804 board 8259 Programmable Interrupt Controller The chip responsible for handling interrupt requests in the PC is the 8259 Programmable Interrupt Controller To use interrupts you will need to know how to read and set the 8259 s interrupt mask register IMR and how to send the end of interrupt EOI command to the 8259 Interrupt Mask Register IMR Each bit in the interrupt mask register IMR contains the mask status of an IRQ line bit 0 is for IRQO bit 1 is for IRQ1 and so on If a bit is set equal to 1 then the corresponding IRQ is masked and it will not generate an interrupt If a bit is clear equal to 0 then the corresponding IRQ is unmasked and can generate interrupts The IMR is programmed through port 21H mar oe e or e a ee en oo For all bits 0 IRQ unmasked enabled 1 IRQ masked disabled End of Interrupt EOI Command After an interrupt service routine is complete the 8259 interrupt controller must be notified This is done by writing the value 20H to I O port 20H 4 10 What Exactly Happens When an Interrupt Occurs Understanding the sequence of events when an interrupt is triggered is necessary to properly write software interrupt handlers When an interrupt request line
27. edures in your program and it can access global data If you are writing your first ISR we recommend that you stick to the basics just something that will convince you that it works such as incrementing a global variable NOTE If you are writing an ISR using assembly language you are responsible for pushing and popping registers and using IRET instead of RET There are a few cautions you must consider when writing your ISR The most important is do not use any DOS functions or routines that call DOS functions from within an ISR DOS is not reentrant that is a DOS function cannot call itself In typical programming this will not happen because of the way DOS is written But what about when using interrupts Then you could have a situation such as this in your program If DOS function X is being executed when an interrupt occurs and the interrupt routine makes a call to DOS function X then function X is essentially being called while it is already active Such a reentrancy attempt spells disaster because DOS functions are not written to support it This is a complex concept and you do not need to understand it Just make sure that you do not call any DOS functions from within your ISR The one wrinkle is that unfortunately it is not obvious which library routines included with your compiler use DOS functions A rule of thumb is that routines which write to the screen or check the status of or read the keyboard and any disk I O routines use DOS a
28. eeeene 1 7 P2 1 0 Connector Pin ASSIpninents zn cce ete ipie arri aa dA aa ah ende Medes 2 4 DMS804 Block Diagrammi mr Ra EB I De ED De 3 3 Master Mode Register Bit Assignments n nnssssnsnssssssssssssssssssssssssssssssss 5 6 Counter Mode Register Bit Assignments esee enne nennen nennen nennen retener nenne entren 5 7 Frequency Scaler Ratio ilaele dedita ec patet e eite ated edet e piede 5 8 iii iv INTRODUCTION The DM5804 dataModule timer counter and digital I O board turns your IBM PC compatible cpuModule M or other PC 104 computer into a high performance timing counting and control system Ultra compact for embed ded and portable applications the DM5804 features Five general purpose 16 bit timer counters in an Am9513A chip 24 timer counter modes of operation Binary or BCD up or down counting On board 5 MHz crystal 24 TTL CMOS 8255 based digital I O lines which can be configured with pull up or pull down resistors Operation from 5 volts only BASIC Turbo Pascal and Turbo C source code diagnostics program The following paragraphs briefly describe the major functions of the board A more detailed discussion of board functions is included in Chapter 3 Hardware Operation and Chapter 4 Board Operation and Programming The board setup is described in Chapter 1 Board Settings Am9513A Timer Counter The versatile Am9513A general purpose timer counter provides a
29. gram sets up the address for the DM5804 registers These addresses are defined at the beginning of Chapter 4 PA BA 0 ADDRESS FOR 8255 PORT A PB BA 1 ADDRESS FOR 8255 PORT B PC BA 2 ADDRESS FOR 8255 PORT C CW BA 3 ADDRESS FOR 8255 CONTROL WORD DR BA 4 ADDRESS FOR AM9513A COUNTER DATA REGISTER CR BA 5 ADDRESS FOR AM9513A COUNTER CONTROL REGISTER IRQEN BA 6 ADDRESS FOR INTERRUPT ENABLE STAT BA 7 ADDRESS TO READ INTERRUPT STATUS IROCLR BA 7 ADDRESS TO CLEAR INTERRUPT STATUS BIT Now reset the Am9513A timer counter chip see Table 5 2 OUT CR amp HFF AM9513A MASTER RESE 5 3 Element Cycle Mode Load Hold Register Register Register Register Master Mode Register 17 Alarm 1 Register 07 Alarm 2 Register OF Status Register 1F NOTE All codes are in hex Next set up the Am9513A master mode register see Figure 5 1 These are the settings we will use Scaler Control binary division Data Pointer Control disable increment Data Bus Width 8 bits FOUT Gate FOUT on FOUT Divider divide by 16 FOUT Source FI see Figure 5 3 Compare 2 Enable disabled Compare 1 Enable disabled Time of Day Mode disabled VALUE HEX 4000 OUT CR amp H17 POINT TO MASTER MODE REGISTER TABLE 5 1 OUT DR amp H0 MAS
30. hat happens to bits 6 and 7 but we can say for sure that bit 5 ends up cleared instead of being set A similar problem happens when you use subtraction to clear a bit in place of the method shown above Now that you know how to clear and set bits we are ready to look at the programming steps for the DM5804 board functions Initializing the Am9513A The Am9513A has a sophisticated internal architecture which is programmed through a series of internal registers These internal registers are accessed by writing to and reading from only two I O port locations the Data Register port at BA 4 and the Control Register port at BA 5 In our example programs we follow these steps to initialize the Am9513A 1 Send a master reset to the Am9513A 2 Point to and set up the master mode register 3 Point to and set up counter 1 mode register 4 Point to counter 1 load register and load desired value 5 Point to and set up counter 2 mode register 6 Point to counter 2 load register and load desired value 11 Point to and set up counter 3 mode register 12 Point to counter 5 load register and load desired value 13 Load and arm counters The examples on the disk and in Chapter 5 will aid you in programming the Am9513A for your application These tools and the data sheet in Appendix C provide a comprehensive description of timer counter operation IMPORTANT Because of the bus release time of the Am9513A AMD recommends you insert a small delay bet
31. ical Support Department 814 234 8087 during regular business hours eastern standard time or eastern daylight time or send a FAX requesting assistance to 814 234 5218 When sending a FAX request please include your company s name and address your name your telephone number and a brief description of the problem CHAPTER 1 BOARD SETTINGS The DM5804 has jumper and switch settings you can change if necessary for your application The board is factory configured with the most often used settings The factory settings are listed and shown on a diagram in the beginning of this chapter Should you need to change these settings use these easy to follow instruc tions before you install the board in your system Note that by installing resistor packs at four locations around the 8255 PPI and soldering jumpers in the desired locations on the associated pads you can configure your 8255 digital I O lines to be pulled up or pulled down This procedure is explained at the end of this chapter Factory Configured Switch and Jumper Settings Table 1 1 lists the factory settings of the user configurable jumper and switches on the DM5804 Figure 1 1 shows the board layout and the locations of the factory set jumpers The following paragraphs explain how to change the factory settings Pay special attention to the setting of S1 the base address switch to avoid address contention when you first use your board in your system Table 1 1 Factory Se
32. interrupt vectors to the state they were in when your program started To restore the IMR write the value that was saved when your program started to I O port 21H Restore the interrupt vector that was saved at startup with either DOS function 35H get interrupt vector or use the library routine supplied with your compiler Performing these two steps will guarantee that the interrupt status of your computer is the same after running your program as it was before your program started running Common Interrupt Mistakes e Remember that hardware interrupts are numbered 8 through 15 even though the corresponding IRQs are numbered 0 through 7 Two of the most common mistakes when writing an ISR are forgetting to clear the interrupt status of the DM5804 and forgetting to issue the EOI command to the 8259 interrupt controller before exiting the ISR 4 13 Example Programs Included with the DM5804 is a set of example programs that demonstrate the use of many of the board s features These examples are in written in C Pascal and BASIC Also included is an easy to use menu driven diagnostics program 804DIAG which is especially helpful when you are first checking out your board after installation C and Pascal Programs These programs are source code files so that you can easily develop your own custom software for your DM5804 Timer Counter INTRPTS Shows how to generate interrupts and read the digital 1 O lines COUNT Shows how to u
33. it bus mode Enable prefetch for write operations Disable prefetch for write operations Master reset Not to be used for asynchronous operations Put the hex number 2710 decimal 10 000 in counter 1 load register OUT CR amp H9 POINT TO COUNTER 1 LOAD REGISTER TABLE 5 1 OUT DR amp H10 COUNTER 1 LSB OUT DR amp H27 COUNTER 1 MSB Next set up the counter 2 mode register see Figure 5 2 These are the settings we will use Gating Control no gating Source Edge rising edge Count Source Selection TCN 1 Count Control disable special gate reload from load count repetitively binary count count down Output Control TC toggled VALUE HEX 0022 5 5 FOUT Divider 0000 divide by 16 0001 divide by 1 0010 divide by 2 0011 divide by 3 0100 divide by 4 0101 divide by 5 0110 divide by 6 0111 divide by 7 1000 divide by 8 1001 divide by 9 1010 divide by 10 1011 divide by 11 1100 divide by 12 1101 divide by 13 1110 divide by 14 1111 divide by 15 FOUT Gate 0 FOUT on 1 FOUT off low Z to gnd Data Bus Width 0 8 bit bus 1 16 bit bus Data Pointer Control 0 enable increment 1 disable increment Scaler Control 0 binary division 1 BCD division Compare 2 Enable 0 disabled 1 enabled Compare 1 Enable 0 disabled 1 enabled
34. m Using Timer Counters 1 2 and 3 This BASIC program COUNT on the example disk shows you how to program the Am9513A s timer counters 1 2 and 3 to perform a simple counting function In this example counter 1 is used to divide the on board 5 MHZ clock by 10 000 The output from counter 1 5 MHz 10 000 500 Hz is used to clock counter 2 Counter 2 is used to divide this 500 Hz clock by 500 The result is a 1 Hz clock which is used to clock counter 3 Counter 3 counts the 1 Hz pulses The count value from counter 3 is displayed on the screen This value should start at 0 and increment once each second 5 MHz COUNTER 1 COUNTER 2 DIVIDER 10 000 DIVIDER 500 COUNTER 3 The first lines of the program clear the screen and set up the base address of the DM5804 The address in the variable BA must match the setting of the base address switch S1 on the board The factory setting of S1 is 300 hex 768 decimal CLS INPUT ENTER BASE ADDRESS IN DECIMAL BA The next section of the program sets up the computer screen CLS CLEAR SCREEN DIM RESULT AS LONG DIMENSION VARIABLE RESULT AS A LONG INTEGER KEY 1 ON TURN Fl KEY ON LOCATE 2 25 PRINT DM5804 COUNTER DEMO PROGRAM LOCATE 10 31 PRI COUNTER 3 VALUE LOCATE 24 2 PRINT F1 QUIT The next section of the pro
35. nd should be avoided in your ISR The same problem of reentrancy exists for many floating point emulators as well meaning you may have to avoid floating point real math in your ISR Note that the problem of reentrancy exists no matter what programming language you are using Even if you are writing your ISR in assembly language DOS and many floating point emulators are not reentrant Of course there are ways around this problem such as those which involve checking to see if any DOS functions are currently active when your ISR is called but such solutions are well beyond the scope of this discussion The second major concern when writing your ISR is to make it as short as possible in terms of execution time Spending long periods of time in your ISR may mean that other important interrupts are being ignored Also if you spend too long in your ISR it may be called again before you have completed handling the first run This often leads to a hang that requires a reboot Your ISR should have this structure Push any processor registers used in your ISR Most C and Pascal interrupt routines automatically do this for you Put the body of your routine here Clear the interrupt bit on the DM5804 by writing any value to BA 7 Issue the EOI command to the 8259 interrupt controller by writing 20H to port 20H Pop all registers pushed on entrance Most C and Pascal interrupt routines automatically do this for you The following C and
36. ng a range of bits is a mixture of setting and clearing operations You can set or clear each bit individually or use a faster method of first clearing all the bits in the range then setting only those bits that must be set using the method shown above for setting multiple bits in a port The following example shows how this two step operation is done Example Assign bits 3 4 and 5 in a port to 101 bits 3 and 5 set bit 4 cleared First read in the port and clear bits 3 4 and 5 by ANDing them with 199 Then set bits 3 and 5 by ORing them with 40 and finally write the resulting value back to the port In C this is programmed as 4 8 v inportb port address v v amp 199 v v 40 outportb port_address v A final note Don t be intimidated by the binary operators AND and OR and try to use operators for which you have a better intuition For instance 1f you are tempted to use addition and subtraction to set and clear bits in place of the methods shown above DON T Addition and subtraction may seem logical but they will not work if you try to clear a bit that is already clear or set a bit that is already set For example you might think that to set bit 5 of a port you simply need to read in the port add 32 2 to that value and then write the resulting value back to the port This works fine if bit 5 is not already set But what happens when bit 5 is already set Bits 0 to 4 will be unaffected and we can t say for sure w
37. ol 000 inactive output low 001 active high terminal pulse count 010 TC toggled 011 not used 100 inactive output high impedance 101 active low terminal pulse count 110 not used 111 not used Gating Control 000 no gating 001 active high TCN 1 010 active high level gate N 1 011 active high level gate N 1 100 active high level gate N 101 active low level gate N 110 active high edge gate N 111 active low edge gate N Fig 5 2 Counter Mode Register Bit Assignments Next set up the counter 3 mode register see Figure 5 2 These are the settings we will use Gating Control no gating Source Edge rising edge Count Source Selection TCN 1 Count Control disable special gate reload from load count repetitively binary count count up Output Control TC toggled VALUE HEX 002A OUT CR amp H3 POINT TO COUNTER 3 MODE REGISTER TABLE 5 1 OUT DR amp H2A COUNTER 3 MODE LSB OUT DR amp H0 COUNTER 3 MODE MSB 5 7 4 BITS p 4 BITS BCD Scaling MM15 1 Binary Scaling MM15 0 With On board With On board Frequency 5 MHz Clock 5 MHz Clock 312 5 KHz 19 53 kHz 1 221 kHz UA F1 10 500 kHz F1 16 Fa Firmo F1 4096 Fs F1 10000 500 Hz F1 65 536 Fig 5 3 Frequency Scaler Ratio F1 F2 F3 F1 1256 F4 F5 76 3 Hz Put the hex number 0000 in counter 3 load register
38. ou install it in your system two sizes are included with the board 4 Holding the board by its edges orient it so that the P1 bus connector s pin 1 lines up with pin 1 of the expansion connector onto which you are installing the board 5 After carefully positioning the board so that the DM5804 s bus connector is resting on the expansion connector gently and evenly press down on the board until it is secured on the connector NOTE Do not force the board onto the connector If the board does not slide into place remove it and try again Wiggling the board or exerting too much pressure can result in damage to the DM5804 or to the module it is being stacked with 6 After the board is installed connect the cable to I O connector P2 on the board When making this connec tion note that there is no keying to guide you in orientation You must make sure that pin 1 of the cable is connected to pin 1 of P2 pin 1 is marked on the board with a small square For twisted pair cables pin 1 is the dark brown wire for standard single wire cables pin 1 is the red wire 7 Make sure all connections are secure External I O Connections Figure 2 1 shows the DM5804 s P2 I O connector pinout Refer to this diagram as you make your I O connec tions 2 3 SRC1 OUT2 GATE2 SRC3 OUT4 GATE4 SRC5 DIGITAL GND EXTINT FOUT DIGITAL GND PA7 PA6 PAS PA4 PA3 PA2 PA1 PA0 PB7 PB5 PB3 PBI 12 VOLTS 12 VOLTS DO OO OO DO
39. pt scheme is used and the processor proceeds with other tasks Then when a keystroke does occur the keyboard interrupts the processor and the processor gets the keyboard data places it in memory and then returns to what it was doing before it was interrupted Other common devices that use interrupts are modems disk drives and mice Your DM5804 board can interrupt the processor when one of the four interrupt sources is enabled through the jumper settings on P3 and P4 By using this interrupt you can write software that effectively deals with real world events Interrupt Request Lines To allow different peripheral devices to generate interrupts on the same computer the PC bus has eight different interrupt request IRQ lines A transition from low to high on one of these lines generates an interrupt request which is handled by the PC s interrupt controller The interrupt controller checks to see if interrupts are to be acknowledged from that IRQ and if another interrupt is already in progress it decides if the new request should supersede the one in progress or if it has to wait until the one in progress is done This prioritizing allows an interrupt to be interrupted if the second request has a higher priority The priority level is based on the number of the IRQ IRQO has the highest priority IRQ1 is second highest and so on through IRQ7 which has the lowest Many of the IRQs are used by the standard system resources IRQO is used
40. r OUT CR amp H9 POINT TO COUNTER 1 LOAD REGISTER TABLE 5 1 OUT DR amp H0 COUNTER 1 LSB OUT DR amp HO COUNTER 1 MSB Next set up the counter 2 mode register see Figure 5 2 These are the settings we will use Gating Control no gating Source Edge rising edge Count Source Selection TCN 1 Count Control disable special gate reload from load count repetitively binary count count up Output Control active high TC VALUE HEX 0029 OUT CR amp H2 POINT TO COUNTER 2 MODE REGISTER TABLE 5 1 OUT DR amp H29 COUNTER 2 MODE LSB OUT DR amp H0 COUNTER 2 MODE MSB Put the hex number 0000 decimal 0 in counter 2 load register OUT CR amp HA POINT TO COUNTER 2 LOAD REGISTER TABLE 5 1 OUT DR amp H0 COUNTER 2 LSB OUT DR amp H0 COUNTER 2 MSB Next set up the counter 4 mode register see Figure 5 2 These are the settings we will use Gating Control no gating Source Edge rising edge Count Source Selection F1 Count Control disable special gate reload from load count repetitively binary count count down Output Control TC toggled VALUE HEX 0B22 OUT CR amp H4 POI TO COUNTER 4 MODE REGISTER TABLE 5 1 OUT DR amp H22 COUNTER 4 MODE LSB OUT DR amp HOB COUNTER 4 MODE MSB Put the hex number 27
41. r must be connected between OUTS pin 16 and GATEI pin 2 at I O connector P2 5 MHz COUNTER 4 COUNTER 5 DIVIDER 10 000 DIVIDER 500 COUNTER 1 INTERRUPT STATUS BIT TRIGGER The first lines of the program clear the screen and set up the base address of the DM5804 The address in the variable BA must match the setting of the base address switch S1 on the board The factory setting of S1 is 300 hex 768 decimal CLS INPUT ENTER BASE ADDRESS IN DECIMAL BA The next section of the program sets up the computer screen CLS CLEAR SCREEN DIM RESULT AS DOUBLE DIMENSION VARIABLE RESULT KEY 1 ON TURN Fl KEY ON LOCATE 2 25 PRINT DM5804 FREQUENCY COUNTER DEMO PROGRAM LOCATE 24 2 PRINT F1 QUIT The next section of the program sets up the address for the DM5804 registers These addresses are defined at the beginning of Chapter 4 PA BA 0 ADDRESS FOR 8255 PORT A PB BA 1 ADDRESS FOR 8255 PORT B PC BA 2 ADDRESS FOR 8255 PORT C CW BA 3 ADDRESS FOR 8255 CONTROL WORD DR BA 4 ADDRESS FOR AM9513A COUNTER DATA REGISTER CR BA 5 ADDRESS FOR AM9513A COUNTER CONTROL REGISTER IROEN BA 6 ADDRESS FOR INTERRUPT ENABL STAT BA 7 ADDRESS TO READ INTERRUPT STATUS IROCLR
42. rrupt data written is irrelevant Each time the interrupt status bit goes high a write should follow to clear the bit x x x x x x x D7 De D5 D4 D3 D2 D1 DO Interrupt Status 0 no interrupt 1 interrupt has occurred 4 6 Programming the DM5804 This section gives you some general information about programming and the DM5804 board Chapter 5 provides some specific programming examples and the Am9513A data sheet in Appendix C provides detailed programming information for all 24 operating modes of the Am9513A These tools will help you as you use the example programs included with the board All of the program descriptions in this section use decimal values unless otherwise specified The DM5804 is programmed by writing to and reading from the correct I O port locations on the board These TO ports were defined in the previous section Most high level languages such as BASIC Pascal C and C and of course assembly language make it very easy to read write these ports The table below shows you how to read from and write to I O ports using some popular programming languages BASIC Data INP Address OUT Address Data Data inportb Address outporto Address Data Turbo Pascal Data Port Address Port Address Data mov dx Address mov dx Address Assembly in al dx Me out dx a In addition to being able to read write the I O ports on the DM5804 you must be able to perform a variety of operations
43. se the Am9513A as a simple counter Digital I O DIGITAL Simple program that shows how to read and write the digital I O lines BASIC Programs These programs are source code files so that you can easily develop your own custom software for your DM5804 Timer Counter COUNT Shows how to use the Am9513A as a simple counter FCOUNT Shows how to create a frequency counter using the Am9513A Digital I O DIGITAL Simple program that shows how to read and write the digital I O lines 4 14 CHAPTERS EXAMPLES OF Am9513A APPLICATIONS This chapter steps through some example programs to help you understand how the Am9513A registers are programmed The data pointer register and command registers are summarized in tables The master mode and counter mode register bit assignments are also included as well as the frequency scaler ratios 5 1 5 2 This chapter provides a more detailed look at some example programs using the Am9513A for counting and timing functions If you are unfamiliar with the Am9513A and how it is programmed walking through these examples and the other example programs included on your DM5804 disk may be the best way to understand the many registers and their operation so that you can successfully develop your own programs for your specific applications IMPORTANT Because of the bus release time of the Am9513A AMD recommends you insert a small delay between software accesses to the chip EXAMPLE Counting Progra
44. set up the control word so that bit 7 is 0 bits 1 2 and 3 are 0 this selects PCO and bit 0 is 1 this sets PCO to 1 The control word is set up like this 0 X X X 0 0 0 1 sets cotti D7 D6 DS D4 D3 D2 D DO written to BA 3 X don t care Set Reset Set PCO Function Bit Bit Select 000 PCO BA 4 Am9513A Data Register Read Write Accesses the Am9513A data register See data sheet included in Appendix C for more information on the operation of the Am9513A IMPORTANT Because of the bus release time of the Am9513A AMD recommends you insert a small delay between software accesses to the chip BA 5 Am9513A Command Register Read Write Accesses the Am9513A command register See data sheet included in Appendix C for more information on the operation of the Am9513A IMPORTANT Because of the bus release time of the Am9513A AMD recommends you insert a small delay between software accesses to the chip 4 5 BA 6 IRQ Enable Write Only Enables and disables interrupt generation Writing a 1 enables interrupt generation writing a 0 disables interrupt generation 0 0 0 0 0 0 0 D7 D6 D5 D4 D3 D2 DI DO Interrupt Enable Disable 0 interrupt disabled 1 interrupt enabled BA 7 Interrupt Status Clear Read Write A read shows the status of the interrupt bit 0 only as defined below A write clears the inte
45. terrupt request line low whenever interrupts are not active So whenever an interrupt request is made the tri state buffer is enabled forcing the output high and causing an interrupt You can monitor the interrupt status through bit 0 in the status word I O address location BA 7 After the interrupt has been serviced the clear command returns the IRQ line low disabling the tri state buffers and pulling the output low again Figure 1 3 shows this circuit Because the interrupt request line is driven low only by the pull down resistor you can have two or more boards which share the same IRQ channel You can tell which board issued the interrupt request by monitoring each board s IRQ status bit NOTE When you use multiple boards that share the same interrupt only one board should have the G jumper installed The rest should be disconnected Whenever you operate a single board the G jumper should be installed CLK IRQ STATUS INTERRUPT REGISTER INTERRUPT Fig 1 3 Pulling Down the Interrupt Request Line P4 Interrupt Source Select Factory Setting EXTINT This header connector shown in Figure 1 4 lets you connect one of four interrupt sources for interrupt generation These sources are PC3 which is the INTRA signal from the 8255 PPI PCO which is the INTRB signal from the 8255 PPI OUTS the output from Am9513A timer counter 5 and EXTINT an external interrupt you can route onto the board through the P2 I O connector
46. that you might not normally use in your programming The table below shows you some of the operators discussed in this section with an example of how each is used with Pascal C and BASIC Note that the modulus operator is used to retrieve the least significant byte LSB of a two byte word and the integer division operator is used to retrieve the most significant byte MSB C 96 amp a b c a b c a b amp c a b c Pascal MOD DIV AND OR a bMODc a bDIVc a bANDc a bORc MOD AND OR PASIG a bMODc a bANDc a bORc Many compilers have functions that can read write either 8 or 16 bits from to an I O port For example Turbo Pascal uses Port for 8 bit port operations and PortW for 16 bits Turbo C uses inportb for an 8 bit read of a port and inport for a 16 bit read Be sure to use only 8 bit operations with the DM5804 4 7 Clearing and Setting Bits in a Port When you clear or set one or more bits in a port you must be careful that you do not change the status of the other bits You can preserve the status of all bits you do not wish to change by proper use of the AND and OR binary operators Using AND and OR single or multiple bits can be easily cleared in one operation To clear a single bit in a port AND the current value of the port with the value b where b 255 2 Example Clear bit 5 in a port Read in the current value of the port AND it with 223 223 255 2 and then write the resulting value to the port In BAS
47. ther PC 104 based system This chapter tells you step by step how to install and connect the board After you have installed the board and made all of your con nections you can turn your system on and run the 5804DIAG board diagnostics program included on your example software disk to verify that your board is working 2 1 2 2 Board Installation Keep the board in its antistatic bag until you are ready to install it in your cpuModule or other PC 104 based system When removing it from the bag hold the board at the edges and do not touch the components or connectors Before installing the board in your system check the jumper and switch settings Chapter 1 reviews the factory settings and how to change them If you need to change any settings refer to the appropriate instructions in Chapter 1 Note that incompatible jumper settings can result in unpredictable board operation and erratic response The DM5804 comes with a stackthrough P1 connector The stackthrough connector lets you stack another board on top of your DM5804 plugging it into the data bus through the pins on the non component side of the board To install the board follow the procedures described in the computer manual and the steps below 1 Turn OFF the power to your system 2 Touch the metal rack to discharge any static buildup and then remove the board from its antistatic bag 3 Select the appropriate standoffs for your application to secure the board when y
48. ttings Switch Factory Settings Jumper Function Controlled Jumpers Installed Connects one of the four sources selected on P4 to an interrupt channel pulls tri state buffer to G ground for buffer P3 ground G for multiple interrupt applications interrupt channels disabled Selects the interrupt source EXTINT Sets the base address 300 hex 768 decimal PPI __ RNG Heecccce US C6 C4 U4 ee A 1l C10 c3 2 Fig 1 1 Board Layout Showing Factory Configured Settings P3 Interrupt Channel Select Factory Setting G Connected Interrupt Channels Disabled This header connector shown in Figure 1 2 lets you connect an interrupt source selected on P4 to an interrupt channel IRQ2 through IRQ7 IRQ10 11 12 14 and 15 can only be used if you have the DM6804 with the AT connector J6 installed To connect the interrupt source selected on P4 to an IRQ channel you must install a jumper across the desired IRQ channel Figure 1 2a shows the factory setting and Figure 1 2b shows IRQ3 selected A A A A s O Q Aa UN o Egg om o ODEN S SL DU DUI Fig 1 2a IRQ Disabled Fig 1 2b IRQ3 Selected Fig 1 2 Interrupt Channel Select Jumper P3 The leftmost pair of pins on P3 labeled G are provided so that you can install a jumper which connects a 1 kilohm pull down resistor to the output of a high impedance tri state driver which carries the interrupt request signal This pull down resistor drives the in
49. ual If any item is missing or damaged please call Real Time Devices Customer Service Department at 814 234 8087 If you require service outside the U S contact your local distributor Board Accessories In addition to the items included in your DM5804 package Real Time Devices offers a full line of board accessories Call your local distributor or our main office for more information about these accessories and for help in choosing the best items to support your board s application Accessories for the DM5804 include the TB50 terminal board and XB50 prototype terminal board for prototype development and easy signal access the DM14 extender board for testing your module and XT50 twisted pair wire flat ribbon cable assembly for external interfac ing Using This Manual This manual is intended to help you install your new board and get it running quickly while also providing enough detail about the board and its functions so that you can enjoy maximum use of its features even in the most complex applications We assume that you already have an understanding of data acquisition and control principles and that you can customize the example software or write your own applications programs When You Need Help This manual and the example programs in the software package included with your board provide enough information to properly use all of the board s features If you have any problems installing or using this board contact our Techn
50. variety of timing sequencing and counting functions The Am9513A chip contains five 16 bit timer counters which can be used individually or internally cascaded to form a counter of up to 80 bits With 24 operating modes up or down counting in binary or BCD and hardware or software gating these timer counters can be easily tailored for a wide variety of applications The timer counters are clocked by an on board 5 MHz crystal The source gate and output for each timer counter is available at the P2 I O connector Digital VO The DM5804 has 24 TTL CMOS compatible digital I O lines which can be directly interfaced with external devices or signals to sense switch closures trigger digital events or activate solid state relays These lines are provided by the on board 8255 programmable peripheral interface chip Pads for installing and activating pull up or pull down resistors are included on the board Installation procedures are given at the end of Chapter 1 Board Settings AT Bus Connector J6 DM6804 The DM6804 is exactly the same as the DM5804 except for the addition of the AT bus connector J6 This allows you to stack the module with CPU s that have the AT bus connectors and access the AT interrupts What Comes With Your Board You receive the following items in your DM5804 package DM5804 interface board with stackthrough bus header Software and diagnostics diskette with BASIC Turbo Pascal and Turbo C source code e User s man
51. ween software accesses to the chip Initializing the 8255 Before you can use the digital I O lines on your DM5804 the 8255 PPI must be initialized This step must be executed every time you start up reset or reboot your computer The 8255 is initialized by writing the appropriate control word to I O port BA 3 The contents of your control word will vary depending on how you want to configure your I O lines Use the control word description in the previous I O map section to help you program the right value In the example below a decimal value of 128 sets up the 8255 so that all 1 O lines are Mode 0 outputs 1 0 0 0 0 0 0 0 D7 D6 D5 D4 D3 D2 Di DO Digital I O Operations Once the 8255 is initialized you can use the digital I O line to control or monitor external devices 4 9 Interrupts What Is an Interrupt An interrupt is an event that causes the processor in your computer to temporarily halt its current process and execute another routine Upon completion of the new routine control is returned to the original routine at the point where its execution was interrupted Interrupts are very handy for dealing with asynchronous events events that occur at less than regular intervals Keyboard activity is a good example your computer cannot predict when you might press a key and it would be a waste of processor time for it to do nothing while waiting for a keystroke to occur Thus the interru
52. y the source code included on your DM5804 program disk in the interrupt programs for a better understanding of interrupt program development Writing an Interrupt Service Routine ISR The first step in adding interrupts to your software is to write the interrupt service routine ISR This is the routine that will automatically be executed each time an interrupt request occurs on the specified IRQ An ISR is different than standard routines that you write First on entrance the processor registers should be pushed onto the stack BEFORE you do anything else Second just before exiting your ISR you must clear the interrupt status of the DM5804 and write an end of interrupt command to the 8259 controller Finally when exiting the ISR in addition to popping all the registers you pushed on entrance you must use the IRET instruction and not a plain RET The IRET automatically pops the flags CS and IP that were pushed when the interrupt was called If you find yourself intimidated by interrupt programming take heart Most Pascal and C compilers allow you to identify a procedure function as an interrupt type and will automatically add these instructions to your ISR with one important exception most compilers do not automatically add the end of interrupt command to the procedure you must do this yourself Other than this and the few exceptions discussed below you can write your ISR just like any other routine It can call other functions and proc
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