PC-31C Manual
Contents
1. 1 4 Installation Requirements XT 286 386 486 Computer Phillips Screw Driver or one to match screw on the computer cabinet and bracket 8 bit or 16 bit bus slot Procedure a Switch off the computer and all attached devices b Unplug power cord from the computer and all attached devices Warning Failure to disconnect all power cables can result in hazardous conditions as there may be dangerous voltage levels present in externally connected cables c Remove the top cover from the PC If you are not sure how to do this consult the manual supplied with the system unit d Choose any 8 or 16 bit expansion slot and remove the screw from the metal bracket fixed corresponding to the chosen slot e Align the gold plated edge connector with the edge socket and the rear adaptor slot with the board bracket Firmly press the board down into the socket on the computer s system board Ensure that the board s edge connector is in the socket and has not slipped sideways past the socket f Replace the screw on the bracket and tighten the screw to the back panel g Replace the computer s cover Plug in all cables and switch the computer power on The PC 31 is now installed 10 CHAPTER 2 Interconnections 2 0 Introduction The PC 31 Eight Port Serial Card plugs into any ISA expansion slot at the gold finger edge connectors J1 J2 and J4 The board communicates to the user circuit via a connector mounted on the PCB2. Bit 4 Bit 5 Bit 6 Bit 7 Delta Clear to Send DCTS Indicates that a Clear to Send input has changd state Delta Data Set Ready DDSR Indicates that a Data Set Ready input has changed state Trailing Edge Ring Indicator TERI Indicates that the Ring Indicator input has changed from a low to a high state Delta Data Carrier Detect DDCD Indicates that the Data Carrier Detect input has changed state Clear to Send CTS This bit is the complement of the Clear to Send input Note Bits DDCD TERI DDSR and DCTS are the sources of the Modem status interrupts These bits are reset when the Modem Status Register is read Data Set Ready DSR Complement of the DSR input Ring Indicator Complement of the RI input Data Carrier Detect DCD Complement of the DCD input 22 3 10 SPR Scratch Pad Register Offset 7 R W It is a 8 bit Read Write Register and does not control the UART in any way It is intended as a scratchpad register to be used by the programmer for temporary data storage SPR Register Offset 7 R W Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 XD7 XD6 XD5 XD4 XD3 XD2 XDI XDO Bits 0 to 7 Data Bits XDO to 7 Allows read write data for temporary storage 23 Chapter 4 Driver Software 4 0 Introduction Full driver software is supplied with the PC 31 package It contains full source code utility programs and a terminal program Note that you do not need t
3. Baud Rate 110 150 300 600 1200 2400 4800 9600 19200 Parity Odd Even or none No of data bits character 7 or 8 No of stop bits character 1 or 2 Each port is referred to as COMn where n 1 8 For example to configure COMS to 9600 baud 8 data bits one stop bit and no parity type the following on the system prompt C gt pc76mode com5 9600 n 8 1 PC76MODE wll either return and re display the configuration or return an error message The COM port and the baud rate must be specified Parity the number of data bits and defaults for data and stop bits are 7 and 1 respectively However at 110 baud the stop bit default to 2 The general form of the PC76MODE command is PCMODE device baud parity databits stopbits where Device is COM1 COM2 COM8 Baud is 110 150 300 600 1200 2400 4800 9600 19200 Parity is n 0 e Databits are 7 or 8 Stopbits are 1 or 2 indicates that it is an optional configuration Warning PC76MODE cannot be used to redirect devices as the standard DOS MODE command does Nor does it support the MODE command s P option where COM1 COM8 devices permanently retry input or output characters see PC76DRVR 25 PCMODE assumes that the PC 31 s I O addresses are as follows COMI 3F8h COM2 2F8h COM3 3E8h COM amp 2E8h COMS 280h COM6 288h COM7 290h COM8 298h DIP SW Settings S1 for the above configuration are SW1 OFF SW2 ON SW3 ON The PC76M
4. 3 8 LSR Line Status Register Offset 5 R W It provides status information to the CPU concerning data transfer LSR Register Offset 5 R W FFRX_ TEMT THRE BI FE PE OE DR Bit 0 Data Ready DR Bit is set to logic 1 it whenever a complete incoming character has been received and transferred into the Receiver Buffer Register This bit is reset by reading the data in the Receiver Buffer Register Bit 1 Overrrun Error OE Indicates that the Receiver Buffer was not read before the next character was transferred into the Receiver Buffer Register thereby destroying the previous character Bit 2 Parity Error PE Indicates that the received data character does not have the correct even or odd parity as selected by the even parity select bit The PE bit is set to logic 1 upon detection of a parity error and is reset to logic 0 whenever the CPU readds the content of the Line Status Register Bit 3 Framing Error FE Indicates that the received character has an invalid stop bit Bit 3 is set to logic 1 whenever the Stop bit following the last data bit or parity bit is a logic 0 Spacing level Bit 4 Break Interrupt BI Bit 4 is set to 1 whenever the received data input is held in the Spacing state logic 0 for longer than the full word transmission time ie the total time of Start bit data bits parity Stop bits This BI bit is reset whenever the CPU reads the contents of the Line Status Register Bit 5 Tranm
5. drivers and demonstration software If any of the items is missing contact your dealer immediately specifying which components are missing Chapter 1 Installation There are two aspects of the PC 31 that must be configured 1 1 The Base Address This address determines where the board is accessed This can be set by a 4 way DIP switch found on the PC 31 Board The address range are 160h to 3F8h The PC 31 serial port occupies a block of 8 consecutive I O addresses The base address setting controls where the block starts This base address must be unique to the PC 31 only and no other card must occupy this address If multiple PC 31 boards are installed in one computer then each board must have a different base address The base address can be assigned to a range of addresses 160h to 3F8h in 8 byte boundaries Table 1 shows the I O addresses occupied by standard interface cards Refer to the Base Address Setting Table in Appendix A for a list of the various base address settings that the PC 31 can occupy The base address setting can be set by adjusting the 4 way dip switch on the PC 31 Offset addresses are fixed and mapped to certain locations In other words each serial port does not necessarily occupy an address offset from the base address For example the Port 1 base address is at 3F8 ie 3F8 to 3FFh while Port 2 base address is at 2F8h The reason for this is to enable the user to adjust the DIP SW in a certain way in order to
6. relates to EPS and STPK bits Table 3 6B determines the parity encoding Even Parity Select EPS Selects even or odd parity if parity bit PEN is enabled See Table 3 6B for parity encoding Stick Parity STKP When bits 3 4 5 are logic 1 the parity bit is transmitted and checked as logic 0 If bits 3 and 5 are 1 and Bit 4 is logic 0 then the parity is transmitted and checked as logic 1 Stick Parity is disabled if bit 5 is 0 See table 3 6B for parity encoding Table 3 6B Parity selections Break Control BKCN It causes a break condition to be transmitted bythe UART When set to logic 1 the serial output SOUT is forced to the spacing state ie logic 0 The break is disabled by resetting bit 6 The break control bit only acts on SOUT and has no effect on the transmitter logic 19 Bit 7 Divisor latch Access Bit DLAB It must be set high to access the Divisor Latches of the Baud Rate Generator during Read Write Setting this bit to 0 allows access to the Receiver Buffer Transmit Holding Register or the interrupt Enable Register see table 4 3 7 MCR Modem Control Register Offset 4 R W This register R W controls the interface with the MODEM or data set MCR Register Offset 4 R W Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 0 0 0 LOOP OUT2 OUTI RTS DTR Bit 0 Bit 1 Bit 2 Bit 3 Bit 4 Bit 5 to 7 Data Terminal Ready DTR This bit is used for output driver control Whe
7. void A repair charge will be levied in the user requires the board to be repaired Before sending the board to your distributor for repairs ensure that you go through Chapter 6 TroubleShooting Hints thoroughly If after you have gone through this Chapter the board still does not work return it for repairs stating in detail what the problem is Our repair service centre will be available to repair our products even after the 1 year warranty A small service fee will be levied which usually covers the cost of the components that are faulty 31 Chapter 8 PC 31 Specifications Computer Host Interface Base Address Bus Type Number of Registers Interrupts Switchable from 0160h to 03f8h in fixed locations XT AT ISA or EISA Eight 8 bit Jumper selectable from IRQ 2 IRQ7 IRQ 10 IRQ 15 Power Requirements 5V DC at t800mA Max UART and External Interface Number of UART Ports Controllers used Transmit Drivers Receive Buffers Oscillator Frequency Baud Rate Data Bits Stop Bits Parity Bits I O connector 8 16C450 Asynchronous Communication ICs 1488 or compatible RS232 1489 or compatible RS232 1 8432MHz Programmable from 50 to 19 2k 5 6 7 or 8 1 1 5 0r2 Odd even or none DB 9 or or DB 25 male connectors Enviromental and Physical Operating temperature Storage temperature Relative humidity Board size Power Requirements 5V 0 C to 55 C 55 C to 150 C 5
8. 3 MODEM Status Interrupt Setting this bit to 1 enables interrupt on clear to send data set ready ring indicator and carrier detect Writing a 0 to this bit disables the MSI Bits 4 to 7 These bits are set to Logic 0 Reading these bits will yield all zeros 3 4 DLM Divisor Latch MSB DLAB 1 offset 1 read write This register is the high order byte of a 16 bit word that divides the on board oscillator frequency to generate the baud rate DLM Register Offset 1 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 D7 D6 D5 D4 D3 D2 D1 DO 3 5 IIR Interrupt Identification Register Offset 2 R W To minimize software overhead during data character transfer the UART prioritizes interrupts into four levels and records these in the IIR ll das Sallie 2 ay aE AE font poe Bit 0 Interrupt Pending When logic 0 it indicates an interrupt is pending and the contents of the interrupt ID register may be used to determines the interrupt source See Table 3 5 Bits 1 3 These bits indicates highest priority interrupt pending if any See table 3 5 Note that IID2 is always 0 in character mode 17 D2 D1 HD2 A Priority Interrupt Type Interrupt Source Interrupt RES CNTRL x 1 x x 1 1 Highest Receiver Line Status Overrurn parity Reading the line or Framing Error status register or Break Interrupt Fea lisa ie Second Receiver Data Reading the Receiver Ready Available Buffer Register FIFO mode o
9. An IDE female header with ribbon cable maps to a DB9 Male of DB25 Female Connector This chapter describes these connectors 2 1 Connections to the IBM Bus The PC 31 board may be plugged into any slot of the computer backplane with the exception of J8 slot of the IBM XTs All data transfers to and from the host computer is channelled via this connector 2 2 IDC 10 Male Header The PC 31 interfaces to the external world via a 10 way IDC male connector header that maps signals to a 9 way or 25 way D type male connector This connector accommodates the following signals 3 RX and TX lines 3 RTS CTS lines 3 DSR DCD DTR and RI lines 3 GND line CLEAR TO SEND CTS REQUEST TO SEND RTS RI RING INDICATOR DATA SET READY DSR CARRIER DETECT DGND DIGITAL GROUND RECEIVE DATA RX DTR DATA TERMINAL READY TRANSMIT DATA TX IDC 10 FEMALE CONNECTOR FRONT VIEW Figure 4 PC 31 Interface Connector as seen from the rear of the PC 11 Figure 4 graphically shows the male header on the PC 31 together with their pin assignments Note that the pin connections refer to the pin numbers of the connector when looking into the connector from the component side of the PC 31 Note that cables that fits onto this male header are provided and maps to a DB 9 or DB 25 These are discussed in section 2 3 12 2 3 COM Port Arrangement The COM ports are arranged in the followi
10. ODE commands can be placed in your AUTOEXEC BAT file which allows automatic setup of the COM ports during bootup Note Under Windows V3 1 WIN 95 or Windows NT you cannot use the above program to initialize the COM ports Use the Control Panel Ports option to configure the COM ports correctly 4 3 The PC76DRVR SYS Device Driver The PC76DRVR SYS contains the example device driver for the eight RS232 ports on the PC 31 It allows the ports to be used in a similiar way files named COM1 to COM8 For example to transmit the PC76READ ME file from the RS232 port COMS you must type copy PC76READ ME gt COM5 PC76DRVR also allows programmers to refer to the ports by their logical names in programs To install PC76DRVR enter the follow line into CONFIG SYS DEVICE PC76DRVR SYS 26 Also ensure that you place the driver in the root directory ie C _ PC76DRVR will be installed when the system is rebooted During booting the following message should be displayed on the computer screen PC 76 drivers v1 1 for COM1 to COM8 installed Before accessing the serial devices ensure that you configure the baud rate etc with the utility program PC76MODE EXE PC76DRVR assumes that the PC 31 s I O addresses are as shown for PC76MODE It performs permanent retries on COM1 COM8 to either input or output characters It will hang if the output is stopped on output or if no input characters are available duri
11. PC 31C 8 Port Serial Card User s Manual For the IBM PC PC XT PC AT PS 2 386 486 Pentium ISA and EISA computers All rights reserved No part of this Publication may be copied stored in a retrieval system or transmitted in any form by any means electronic mechanical by photocopying recording or otherwise in whole or in part without prior written permission from the Publishers Third Edition 29 July 1996 July 1996 Printing Information furnished in this manual is believed to be accurate and reliable however no responsibility is assumed for its use nor for any infringements of patents or other rights of third parties which may result from its use IBM IBM PC XT AT and IBM PS 2 are trademarks of International Business Machine Corporation MicroSoft and MSDOS are trademarks of MicroSoft Corporation We acknowledge all other trademarks from companies mentioned in this User s Manual Copyright S Allie and Eagle Technology Table of Contents Introduction Features PC 31 Package Typical Applications Chapter 1 Installation 1 1 Setting the Base Address Table 1 Address for typical I O addresses 1 2 Interrupt Jumper Settings Figure 3 Interrupt Jumper Settings Table 2 Standard Interrupt Settings 1 3 Interrupt Enable Disable Jumpers Figure 3a IRQ Enable Disable Jumper Settings 1 4 Installing the PC 31B C in your Computer Chapter 2 Interconnections 2 0 Introduction 2 1 Connections to Backp
12. Table 1 1 Base Address Switch Settings 1 2 Interrupt Jumper Settings Each COM port can control an interrupt level To allow the PC 31 to send interrupts to the system bit 3 of the Modem Control Register must be set high Refer to figure 3 for the interrupt jumper settings 2 4 6 10 12 2 4 6 10 12 2 4 6 10 12 2 4 6 10 12 OOWO OO OO OBooo OGOOGO OOOO OOGO OWOoOOO OBOooo OG OOo OOOO OOOHOO OWOOO 3 5 71115 3 5 71115 3 5 71115 3 5 71115 IRQ 2 IRQ 3 IRQ 4 IRQ 5 2 4 6 10 12 2 4 6 10 12 2 4 6 10 12 2 4 6 10 12 OOOO COLONIC OOGO OO0OO0OO0OQO OOOO OOOO OOO OOOO9O SELL Ole O O O WO OO Or OOO 3 5 71115 3 5 71115 3 5 71115 3 5 71115 IRQ 10 IRQ 11 IRQ 12 IRQ15 Figure 3 Interrupt jumper settings In a standard PC the interrupt levels are allocated as follows Level Level Allocation IRQO System timer IRQ1 Keyboard IRQ2 IRQ9 Display Adaptor IRQ3 COM 1 if installed IRQ4 COM2 if installed Floppy disk controller LPT1 if installed Table 2 Standard interrupt settings On PC ATs IRQ is used by the system board itself and any interrupt requests on IRQ2 is transparently re routed to IRQ9 The default IRQ setting on the PC 31 is IRQ4 Note that unless the interrupt line is specifically enabled by software by setting bit 3 of the Modem Control Register MCR high the inte
13. does not respond Under Windows NT system boots but BUS mouse does not respond Under Windows NT system crashes in middle of booting sequence Repair Service Specifications Appendix A Layout Diagram 33 Page 24 24 24 25 26 27 27 28 29 29 29 29 29 29 30 30 31 32 Introduction The PC 31B C 8 port serial card is an industrial interface card used to communicate with various devices asynchronously via the IBM PC XT AT Each card provides eight standard RS232 interface ports spanning from COM1 thru to COM8 Each of the COM ports can be configured with its own unique interrupt line The serial interface is implemented with a 16450 UART connected to associated drivers The 16450 UART is a faster version of the 8250 formerly found on IBM XT models The PC 31 fits into one of the IBM ISA expansion slots Typical applications Controlling PLCs Laboratory Automation Data Logger via RS232 Product testing Energy management Features Controls up to 8 external devices per board Multiple boards are accommodated Interrupt selectable from IRQ 2 3 4 5 6 7 10 11 12 15 Driver software in C plus demostration and test programs Commercial programs like Telix Testpoint and DasyLab fully supports the PC 31 PC 31 Package The PC 31 package consists of PC 31 Interface Card PC 31 User s Manual 8 cable connectors IDC to DB25 DB9 One 5 25 or 3 5 diskette containing the PC 31
14. ificant bit MSB RBR Receiver buffer register read mode XD7 Reading this register gives the current data translated by the UART THR Transmit Hold register write mode XD7 Writing a byte to this register hold the current byte to be transmitted by the UART 3 2 DLL Divisor Latch LSB DLAB 1 offset 0 read write This register is the low order byte of a 16 bit word that divides the on board oscillator frequency to generate the baud rate DLL Register Offset 0 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 D7 D6 D5 D4 D3 D2 D1 DO 3 3 INTEN Interrupt Enable register DLAB 0 offset 1 read write This register enables the four types of UART interrupts Each interrupt can individually activate the INTR output line It is also possible to totally disable the interrupt system by resetting bits 0 thru 3 of this register INTEN Register R W mode jojo O MSI RLSI THREI RDAI Bit 0 LSB Receive Data Available interrupt Setting this bit to 1 enables the Receive Data Available Interrupt Writing a 0 to this bit disables the RDAI Bit 1 Transmit Holding Register Empty Interrupt Setting this bit to 1 enables the Transmit Holding Register Empty Interrupt Writing a 0 to this bit disables the THREI 16 Bit 2 Receive Line Status Interrupt Setting this bit to 1 enables interrupt on overrun parity framing errors and break indication Writing a 0 to this bit disables the RLSI Bit
15. ith the PC31 s operation Disable the COM ports and rerun test software If the problem persists then try changing the IRQ of the serial port and rerun test software or commercial COMs software like TELIX COMBIOS etc The PC 31 should work If the test still fails then the PC 31 is faulty Return the board to your distributor for repairs Tx line does not transmit data at all Try a different COM port on the PC 31 Card If the Tx line on this COM port is fully operation then it is possible that the Line driver on the PC 31 is faulty Return to your distributor for repairs Rx line does not respond at all Try a different COM port on the PC 31 Card If the Tx line on this COM port is fully operation then it is possible that the Line driver on the PC 31 is faulty Return to your distributor for repairs System hangs when PC 31 is placed in the computer It could be as a result of another Card conflicting with the PC 31 s I O Base Addresses Try a base different address If it still fails then the PC 31 is faulty return to your distributor for repairs COM Port at Header H5 and Header H6 are not responding during setup The User probably assumed that Header H5 is COM Port 5 and Header H6 is COM port 6 This is NOT correct COM port 5 header number is H6 with IRQ Jumper JP5 and COM port 6 Header is H5 with IRQ Jumper JP6 29 Problem Solution Problem Solution Under Windows NT or Windows 95 the system boots up cor
16. itter Holding Register Empty TMRE This bit indicates that the UART isready to accept a new for transmission It also causes the UART to issue an interrupt to the CPU when the Transmit Holding Register Empty Interrupt Enable is set high The THRE bit is set to 1 when a character is transferred from the Transmitter Holding Register into the Transmitter Shift Register The bit is reset to logic 0 when writing to the Transmitter Holding Register Bit 6 Transmitter Empty indicator TEMT This bit is set to 1 whenever the Transmitter Holding Register THR or the Transmitter Shift Register TSR are both empty TEMT is reset by writing a character to the Transmitter Holding Register 21 Bit 7 FIFO Receiver Error FFRX Bit is permanently set to logic 0 in the 16450 and 16550 character mode In the 16C550 FIFO mode this bit indicates one or more parity errors framing errors or break indications in the receiver FIFO FFRX bit is reset when a read cycle is initiated on the Line Status Register 3 9 MSR Modem Status Register Offset 6 R W Provides the current state of the control line from the MODEM or peripheral device to the CPU In addition to current state information four bits of the MODEM Status Register provide change information This bits are set whenever a control input from the MODEM changes state These bits are reset upon initiation of a CPU read cycle to the MODEM Status Register MSR T egisi een 6 R W Bit 3
17. lane of PC 2 2 IDC 10 Male Connector Figure 4 PC 31 Interface IDE Connector 2 3 COM Port Arrangement Table 2 3a COM Port Arrangement 2 4 DB9 DB25 User Connector Figure 5 PC 31 DB9 DB 25 Interface Connector Chapter 3 Register Structure 3 0 Introduction Table 3 0 PC 31 Register Structure 3 1 RBR Receiver Buffer Register 3 2 DLL Divisor Latch LSB Register 3 3 INTEN Interrupt Enable Register 3 4 DLM Divisor Latch MSB Register 3 5 IIR Interrupt Identification Register Table 3 5 Interrupt ID bit definitions 3 6 LCR Line Control Register Table 3 6 Word Length and Stop Bit Selections Table 3 6b Parity Selection 3 7 MCR Modem Control Register 3 8 LSR Line Status Register 3 9 MSR Modem Status Register 3 10 SPR Scratch Pad Register Page Be ee ee Manan ee Ol ee cee ce ce ee jm WWW WR Re eS eS m Chapter 4 Table of Contents Continued Driver Software 4 0 Introduction 4 1 PC76 Software Package 4 2 PC76MODE utility program 4 3 PC76DRVR DOS Device Driver 4 4 PC76TALK COM Terminal program 4 5 PC76TEST COM test program Chapter 5 Chapter 6 Problem 1 Problem 2 Problem 3 Problem 4 Problem 5 Problem 6 Problem 7 Chapter 7 Chapter 8 Testing the PC 31 Card Troubleshooting the PC 31 Board does not respond Tx line does not transmit data Rx Line does not receive data correctly System hangs when PC 31 is plugged into computer COM Port 5 and 6
18. map the ports to standard DOS Serial Ports Table 1 Addresses for standard I O devices 000 1FF Internal system board 200 20F 210 217 220 24F 250 257 258 25F 278 26F reserved 280 2EF 2F0 2F7 300 31F Prototype Board 320 32F 330 377 378 37F 380 38F SDLC communications 390 39F 3A0 3AF Binary comms 3B0 3BF Mono Display Adaptor 3C0 3CF 3D0 3DF 3E0 3E7 3E3 3EF 3F0 3F7 Floppy disk 3F8 3FF COM1 400 FFF Not used see below Table 1 Standard I O Addresses The PC 31 DIP SW is described in figure 1 below TLL Figure 1 Dip Switch 4 not used Care should be taken to ensure that the PC 31C I O addresses is not being used by other devices in the PC If your computer has boards not listed in Table 1 such as IDE I O Card LAN adaptors back up boards or other engineering boards you should consult the User s Manual for these boards for information on the address ranges used In most cases base address of 2A0h for the 1st Port is a good choice Address 2A0h is also the factory default base address setting Swi Sw2 SWS PORTI PORTZ PORTS PORTS PORTS PORTS PORT PORTS KAAKA 3FF 2B7 2BF 1A7 1AF 1B7 1BF ON ON OFF 160 es 170 178 180 188 190 198 ON LO Lier tes ir ON OFF ON 2A0 2A8 2B0 2B8 1A0 1A8 1B0 1B8 S oar aae 27 2FF 2AF 2B7 2BF 1A7 1AF 1B7 1BF 3FF 2FF SEE 2EF 287 28F 297 29F 217 21F 227 22F 237 23F 247 24F ZE e e eee
19. n this bit is set to logic 1 the DTR line ie on the DB9 connector is forced to a logic 0 Request To Send RTS This bit controls the Request to Send line It affects the RTS line in the same manner as bit 0 Output 1 OUT1 This bit controls the Output 1 line which is an auxilliary user output It effect the OUT 1 line in the same manner as bit 0 Output 2 OUT2 This bit controls the Output 2 line which is an auxilliary user output It affects the OUT 2 line in the same manner as bit 0 Loopback Enable LOOP This bit provides a local loopback feature for diagnostic testing of the UART When bit 4 is set high the transmitter shift register is internally connected to the receiver shift register the four MODEM control inputs DSR CTS RI and DCD are disconnected and the four MODEM control outputs are internally connected to the four MODEM control inputs The MODEM control output pins are forced to their inactive state high In a loopback mode the data transmitted is received immediately This allows the CPU to verify the transmitted and received data paths of the UART The transmitter and receiver interrupts are fully operational The MODEM Control Interrupts are also operational but the interrupt sources are now the lower four bits of the MODEM Control Register instead of the four MODEM Control Inputs The Interrupts are still controlled by the Interrupt Enable Register These bits are permanently set to logic 0 20
20. ng input Note The PC76DRVR does not support IOCTL calls although the entry points to the various functions are provided in the source code PC76DRVR ASM 4 4 The PC76TALK COM Terminal Program PCTALK COM is a simple terminal emulator which is included as an example of using interrupts with the COM ports As supplied it will operate in full duplex via COM1 emulating a subset ofthe Televideo 950 control codes It uses IRQ 4 default and must be selected by jumper on the PC 31 before the emulator is run Baud rate parity data and stop bits must be set up using PC76MODE before running the terminal program Note that PC76TALK COM does not use the PC76DRVR device driver To exit from PC76TALK use any special function key such as F1 The program explains how to modify the program to run in half duplex use different IRQs and use other COM channels 4 5 The PC76TEST COM PC76TEST COM is a very simple terminal emulator written in C which can be configured to communicate with any of the PC 31 COM ports This program is provided to allow users to test simple serial I O via any serial ports It also gives an example of how to write your own C based comms applications without the need to use an Assembler 27 Chapter 5 Testing the PC 31 Before attempting to interface the PC 31 with your application it is essential that you test the board first This is done using the following Procedure Install the PC 31 using the p
21. ng order on REV 1C Boards HEADER ARRANGEMENT COM PORT 1 COM PORT 2 COM PORT 3 COM PORT 4 COM PORT 6 COM PORT 5 COM PORT 7 COM PORT 8 Table 2 3a COM Port Arrangement Note Some of the COM ports and associated headers incremental are not in sequence Ensure that you follow the above table at all times Also check if the PC 31B C you have is marked REV 1C The template is given in the layout diagram section 2 4 User Connector The PC 31 interfaces to the external world via a 10 way IDC connector that maps signals to a 9 way or 25 way D type male connector fp X DIGITAL GROUND DG D a a14 TRANSMIT DATA TX 20 45 o RECEIVE DATA RX 20 46 o REQUEST TO SEND RIS o 47 Sie 1 CLEAR TO SEND CTS e CARRIER DETECT DCD a CTs p ale j o DATA SET READY DSR DATA SET READY DSR gt 49 RECEME DATA RX 40 3 7 3 REQUEST TO SEND RTS SIGNAL GROUND SCND 20 TRANSMIT DATA 1x 29 g Bis ea te DERMAL READY DATA TERMINAL READY DTR Lo 97 J OLAR TO SEND CIS ARRIER DETECT 0 eA DETECT DED j a21 RI RING INDICATOR 5 31 RING INDICATOR RI o a8 DIGITAL GROUND DGND 120 o 10 7 114 9 2 o2 3 08 o Ta Figure 5 PC 31 Interface Connector as seen from the rear of the PC Figure 5 graphically shows the connector together with their pin assignments Note that the pin connections refer to the pin numbers of the connector when looking into the connec
22. nly 1 Third Transmitter Holding Transmit holding Reading the IIR Register Empty Register Empty Register if source of interrupt or writing into the Transmitter Holding Register Fourth MODEM Status Clear to Send Reading the Data Set Ready MODEM Status or Ring Register Indicator or Data Carrier Detect Table 3 5 Interrupt Identification Bit Definitions 3 6 LCR Line Control Register Offset 3 R W This register is a R W register located at Base Address 3 The format of the asynchrounous data communications exchange and setting the divisor latch access bit is set via the Line control register ll Register Offset 2 R W Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 DLAB BRCTL STKP EPS PEN STB WLSH_ WLSL BitO amp 1 Word Length Select WLSx Determines the number of data bits per character The encoding of the data bits are shown in table 3 6 18 Bit 2 Bit 3 Bit 4 Bit 5 Bit 6 B WLS1 WLSO Word Length Stop bits WLS1 0 0 1 1 0 0 1 1 2 0 0 0 0 0 0 0 1 1 1 1 Table 3 6 Word Length and Stop bit selections Numter of Stop Bits STB Sets the number of stop bits per character See WLSx bits and Table 3 6 Parity Enable PEN Enables parity on transmission and verification on reception Parity enable bit The parity bit is used to produce an even or odd number of 1s when the data word bits and the parity bit are summed This bit also
23. o use the driver library Most commercial communications programs like Telix Crosstalk COMBIOS etc supports the PC 31C All that is required in these packages is the I O base address of the COM port and the Interrupt Request Line IRQ used Third Party Driver libraries can also be used with the PC 31C Commercial packages like Testpoint DasyLab etc has a RS232 Driver libraries available This can be used without any problems 4 1 The PC 76 Software Package This package provides an introduction to the PC 31C and includes source code so that the files may altered to suite user applications Quick reference is given below Program name Description PC76READ ME Text file that describes the PC 76 software package PC76MODE EXE Utility program that configuresthe PC 31 s eight COM ports PC76MODE C C source code for the above utility program PC76DRVR SYS DOS Device driver that control the PC 31 s COM ports PC76DRVR ASM Source code for the above device driver PC76TALK ASM Assembly source code for PC76TALK COM terminal program PC76TALK COM Simple terminal program PC76TEST EXE Test program that checks the PC 31 COM ports PC76TEST C C source code for the above test program See the PC76READ ME manual for detailed documentation on the PC 76 24 4 2 PC76MODE utility program This program allows the user to configure the operational parameters for any of the eight RS232 ports on the PC 31 The parameters that may be configured are
24. rectly but the BUS Mouse NOT serial mouse does not work The BUS mouse uses IRQ 12 If this IRQ line is enabled on the PC 31 via LK2 and the COM port Jumper any of JP1 thru JP8 then the Mouse will fail to operate The BUS mouse also uses IRQ 12 hence you must not use this IRQ line for the COM ports I suggest you disable the IRQ 12 line completely using the LK2 Jumper In other words remove the Jumper under I12 on LK2 Your system should operate normally Under Windows 95 or NT the system boots up but crashes in the middle of the booting process It could be as result of an I O base address conflict with the PC 31 Board and your network Card I suggest that you check your network card s base address If it overlaps with the PC 31 the system will crash The solution would be to change the base address of the Network Card Warning Any parts replaced on the PC 31 must be done by a qualified or trained technician If you the user is not a trained technician then rather return the board to your distributor for repairs explaining in detail what the problem is If you cannot solve the problem then simply call your distributor for immediate help 30 Chapter 7 Repair Service The PC 31 is guaranteed for a period of year If the board is faulty within this period we will gladly repair it free of charge provided that the maximum specifications was not exceeded If any burn t tracks are seen on the PC 31 Board warranty will be
25. rocedure described in the Chapter 2 Installation Proceed as follows Switch the Computer on On the DOS prompt run the program PC76TEST COM The program will display instructions PC 31TEST Talk to ANY 8250 serial channel at any addresss N Set COM Address T Talk via efault base address SC Bit If you want to test a serial port at a different base address then select N on the program menu and enter the base address or COM port 1 to 8 To test the COM port type T If any error messages are displayed then the PC 31 was not installed at that address Try a different base address eg 2F8h and re run the test S W If the problem persists then try changing the IRQ line as specified in Chapter 2 and rerun test software The board should work You can also use other commercially available utilities like QAPLUS from Diagsoft or CHECKIT These utilities test the serial ports internal registers internal loopback data as well as external loopback data at specific Baud rates 28 Chapter 6 Troubleshooting Problem Solution Problem Solution Problem Solution Problem Solution Problem Solution The PC 31 board does not respond at specified base address Another I O card might be using the same base address location as the PC 31 The most common card that can cause conflicts is your IDE I O card This card contains two serial port ie COM1 and COM2 that will interfere w
26. rrupt output from the PC 31 is tri stated ie not connected It is also tri stated upon power up 1 3 Interrupt Enable Disable Jumpers The IRQ line on the PC 31B C Board are driven low using the 220R SIP Certain non compatible computer cards does not like this type of configuration Provision was hence made to disconnect the unused IRQ lines from the ISA BUS completely By removing the jumper you automatically disconnect the IRQ line from the BUS Examples of jumper settings are as follows LK1 LK2 LK1 LK2 IRQ EN DIS IRQ EN DIS IRQ EN DIS IRQ EN DIS OO0O00O O Opoo O O OOOO O OBOO O O I2 13 14 I5 16 I7 110 111112 115 12 13 14 15 16 I7 10 111112 115 IRQ 2 ENABLED IRQ 11 ENABLED IRQ 2 3 4 7 ENABLED IRQ 10 11 15 ENABLED LK1 LK2 LK1 LK2 IRQ EN DIS IRQ EN DIS IRQ EN DIS IRQ EN DIS WOW OOO Orn OO Oo OO OO0000 QOO O M O QQ 12 13 14 I5 l6 I7 110 111112 115 12 13 14 15 16 I7 110 111112 115 ALL IRQs DISABLED ALL IRQs DISABLED IRQ 2 3 7 ENABLED IRQ 10 15 ENABLED Figure 3a IRQ Enable Disable Jumper Settings Note You must first enable the IRQ line using the above jumpers before setting the IRQ line JP1 to JP8 of the COMs Ports COM port failure will result if the IRQ line is not enabled via LK2 or LK1
27. to 90 non condensing 170mm x 106mm 5V DC at 800mA Max 32 APPENDIX A Layout Diagram
28. tor from the rear of the computer Also note that the pin numbers are embossed on the connector itself 14 CHAPTER 3 Register Structure 3 0 Introduction At the lowest level the PC 31 can be programmed using I O input and output instructions This chapter contains the information on all the PC 31 registers Although programming the board is not difficult it is time consuming and requires detailed knowledge of the PC 31 as well as the operation of the host PC and its operating system In order to simplify the process a set of driver libraries is provided The use of these libraries allow access to all the board s functions and is described in Chapter 5 Programming guide The serial port on the PC 31 occupies 4 consecutive addresses in the computer s I O space The layout of these registers are shown in Table 4 PC 31 COM Port register structure The offset of the registers are given as offset addresses from the base address of the board This base address is set with the Dip Switch as detailed in Chapter 2 Installation Offset DLAB Read Write Read Write Oo U HF eA me E e o l DLL EA Ea ll S IER A DLH 2 Interrupt ID register Line Control Register LCR Modem control Modem Status Register MSR Table 3 0 PC 31 register structure 15 3 1 Receiver Buffer Register offset 0 read This register holds the byte received Bit 0 is the least significant bit LSB while Bit 7 is the highest sign
Download Pdf Manuals
Related Search