An0044 - Eurotech
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1. RS232 422 485 Figure 1 J7 J12 serial connector layout N Note in the previous figure a red square pad indicates pin 1 of each connector EuroTecH 8 COM 1270 High speed serial ports J7 J14 Serial Ports in RS232 mode The following table shows the pinout of the J7 J14 serial connectors in RS232 mode Table 1 J7 J14 connectors in RS232 mode Pin Signal Function In Out DB25 DB9 1 DCD Data Carrier Detect In 8 1 2 DSR Data Set Ready In 6 6 3 RX Receive Data In 3 2 4 RTS Request To Send Out 4 7 5 TX Transmit Data Out 2 3 6 CTS Clear To Send In 5 8 7 DTR Data Terminal Ready Out 20 4 8 RI Ring Indicator In 22 9 9 10 GND Signal Ground 7 5 J7 J10 Serial ports in RS422 mode The following table shows the pinout of the J7 J10 serial connectors with RS422 mode Table 2 J7 J10 connectors in RS422 mode Pin Signal Function In Out 1 TX Transmit Data Out 2 Not connected 3 TX Transmit Data Out 4 Not connected 5 RX Receive Data In 6 Not connected 7 RX Receive Data In 8 Not connected o ess o 2 Signal ground J7 J10 Serial ports in RS485 mode The following table shows the pinout of the J7 J10 serial connectors with RS485 mode Table 3 J7 J10 connectors in RS485 mode Pin Signal Function In Out TX RX Transmit Receive Data Out In Not connected TX RX Transmit Receive Data Out In Not connected Not connected Not con2. e Ug ino Sc F iE jeE a cj E 5 gt lt us RE on ee e _ 14 add ers i mr ed 18 Cis RIA oe moll ef E mart Lene crit me m i firn Ris F22 ps raat R3 C3B C17 ABR Uii raf 120 i U c RPX2 cra CFM ent RPXB 1 JE CJ eo f es er 14 i G om Us RIDE ere py hs call Ote Hn E43 nT tooo i mm ea ou z Ud amp M7 MB M4 M12N3 Hume Figure 5 COM 1270 Assembly Bottom drawing EuroTecH 16 COM 1270 High speed serial ports If you need to move the JPS2 solder jumper position please note that between pin 1 and 2 there s a wire on the PCB that must be cutted to prevent conflicts The 2 3 JPS2 position is necessary if you want to send a custom clock to the Exar ST16C554 chipset To prevent damages to the board all the modifications described in this chapter have to be made by technical prepared personnel EuroTecH COM 1270 High speed serial ports Chapter5 Exar ST16C554 Register List This chapter is dedicated to list all the Exar ST16C554 registers as a short reference for the programmer For a detailed description of each register please refer to the component data sheet A2 A1 A0 General Register Se 00 0 RHR XX bit 7 bito 000 THRIXX bit 7 bito 0 0 1 IER OO 0 receive status holding interrupt register interrupt 010 FCR
3. 16 554 16 554 RS232 i or Bypass O EEPROM RS422 485 RS232 driver EU D 1 Glue Logic Jj g RS422 485 RS232 driver a ae j RS422 485 or Bypass Figure 2 Block diagram The serial hardware architecture may be divided into the following main subsections Serial chipset section two Exar ST16C554 chipsets Clock syntetizer Glue Logic Serial port driver section EuroTecH COM 1270 High speed serial ports 11 Exar ST16C554 chipsets The core of the serial functionality of the COM 1270 board is based on two Exar ST16C554 chipsets quad UART with 16 byte fifo s each chipset provide four serial ports For detailed information about the Exar ST16C554 chipset please refer to the technical data sheet Baud rate of the serial transmission may be programmed by software accessing serial register the baud rate depends on the Clock input frequency applied to the pin 26 of the chipset the following relation describe the baudrate versus the input frequency Baudrate Input Frequency 16 Clock This component can reach speeds of receives trigger levels and data rates up to 1 5Mbps with a clock reference of 24MHz As an example we reports the following table for the derived baudrates starting from two clock reference 1 8432 MHz Clock and 7 3728 MHz Clock User User DLM DLL Output Baud Rate Output Baud Rate 16 Clock 16xClock Program Value Program Value 1 843
4. RCVR DMA XMIT FIFO trigger mode FIFO enable MSB select reset 01 0 ISR O1 FIFO s INT INT INT enabled priority priority status bit 2 bit 1 0 1 1 LCR 00 divisor stop word latch bits length enable bito MCR 00 0 DTR 10 1 5660 FIFO trans tans break framing parity overrun receive data empty holding interrupt error error error data error empty ready 110 MSR XO0 CD RI DSR CTS delta delta delta delta CD RI DSR CTS 1 1 1 SPR FF bit 7 bit bit 5 bit bit 3 bit 2 bit 1 bito Special Register set Note 2 Note 2 The Special register set is accessible only when LCR bit 7 is set to 1 ST16C554 Register Table 7 EuroTecH 18 COM 1270 High speed serial ports Chapter 6 Pratical example Suppose you want to connect an high speed RS232 device operating at 500Kb to the COM 1270 First of all you have to know that only J11 J14 J13 and J12 may be used to connect this device because it hasn t speed limitation operating in TTL mode Running at 500Kb need some hardware modification removing the U16 U17 U18 U19 RS232 serial drivers and install a 0 Ohm resistor packs CAT16 package for RP9 RP10 RP11 RP12 RP13 RP14 RP15 and RP16 this allow you to output TTL serial level You ve then to make the proper baud rate selection looking at the following relation you can find the proper Clock Divisor knowing that the Input Frequency is Baudrate Input Frequency 16 Clock Divisorpgc The Clock Divis
5. 2 MHz Clock 7 3728 MHz Clock Divisor Divisor Decimal HEX HEX HEX 50 200 2304 900 09 00 300 1200 384 180 01 80 600 2400 192 CO 00 CO 1200 4800 96 60 00 60 2400 9600 48 30 00 30 4800 19 2K 24 18 00 18 9600 38 4k 12 0C 00 0C 19 2k 76 8k 6 06 00 06 38 4k 153 6k 3 03 00 03 57 6k 230 4k 2 02 00 02 115 2k 460 8k 1 01 00 01 Table 1 ST16C554 programming baud rates Serial port frequency baud generator To operate properly the Exar 16C554 chipset needs an external clock source internally differents baud rates may be programmed as described in the following of the document The primary clock source is generated by an external programmable CT2292 clock syntethizer Ref U3 chipset on Figure 3 which generates custom clock syntesys starting from a 14 7456MHz 50ppm reference crystal Figure 3 show the schematic section of the clock syntetizer which generated two clocks the CLK_SER_IN1 and CLK SER IN2 clock for Exar ST16554 chipsets and a clock reference for the CAN section EuroTecH 12 COM 1270 High speed serial ports cris T o g T 2 g s XBUF 6 6 Wo 2 o Figure 3 COM 1270 CY2292 Clock synthetizer section The COM 1270 has the capability to be customized to make frequency selection for the CY2292 installing or not the components listed below to set FSW2 to a logic zero mount R14 to set FSW1 to a logic zero mount R15 to set FSWO to a logic zer
6. EmbeddedDNA EuroTecH THE COMPLETE EMBEDDED PC SOLUTION COM 1270 High speed serial ports Rev 1 0 Nov 2004 COPYRIGHT 1994 2004 Eurotech S p A All Rights Reserved COM 1270 High speed serial ports ABOUT THIS MANUAL This application note is intended to describe the COM 1270 high speed serial ports capability EurolecH THE COMPLETE EMBEDDED PC SOLUTION Via J Linussio 1 33020 AMARO UD ITALY Phone 39 0433 485 411 Fax 39 0433 485 499 web _ http Awww eurotech it e mail sales eurotech it NOTICE Although all the information contained herein has been carefully verified Eurotech S p A assumes no responsibility for errors that might appear in this document or for damage to property or persons resulting from an improper use of this manual and of the related software Eurotech S p A reserves the right to change the contents and form of this document as well as the features and specifications of its products at any time without notice Trademarks and registered trademarks appearing in this document are the property of their respective owners EurolecH COM 1270 High speed serial ports Conventions The following table lists conventions that are used throughout this guide Icon Notice Type Description Important features or Information note instructions potential damage to a program System or device or potential personal injury Warning i Information to alert you to Euro
7. Remove U17 install OOhm CAT16 Resistor Pack RP15 RP16 Remove U19 install CAT16 Resistor Pack RP13 RP14 Remove U18 install OOhm CAT16 De EE Resistor Pack RP11 RP12 Table 5 TTL Hardware modifications To modify the reference clock of the Exar ST16C554 you ve to configure the R14 R15 and R16 RO805 resistors as described in the folowing table Serial J12 U17 installed J13 U19 installed R14 R15 R16 Frequency Mounted Mounted Mounted 23 96160 Mounted Mounted Removed 22 11840 Mounted Removed Mounted 18 43200 Mounted Removed Removed 16 58800 Removed Mounted Mounted 14 74560 Removed Mounted Removed 11 05920 Removed Removed Mounted 9 21600 Removed Removed Removed 7 37280 factory default Table 6 R14 R15 R16 settings EuroTecH COM 1270 High speed serial ports 15 The following images report the assembly drawing of the COM 1270 Rev B board allowing you finding reference components for modification 2 JPS5 JPS4 JPS3 IPS amp JPS1 d 1 Ut j Lr B C crz Eas TEHE R67 Tr RP23 RP25 22500000909 Figure 4 1270 Assembly top drawing 1850 043 L 1048 651 R52 10 1045 R497 e4 RP6 257 H eg ELI sp m EJ D gt lt EN P
8. Speed limitation J9 vee High Speed limitation High Speed limitation J10 High Speed limitation High Speed limitation High Speed compliant in TTL J11 3 Ves mode without serial driver J12 High Speed compliant in TTL X mode mode without serial driver High Speed compliant in TTL J13 Ves mode mode without serial driver J14 High Speed compliant in TTL mode mode without serial driver Table 4 COM 1270 configuration modes Note that high speed serial communications are compliant only for J11 J12 J13 and J14 ports operating in TTL This may be reached making the proper modifications to the hardware board 1 The Enable Disabile functionality and the operative mode of the serial ports may be selected by pair EuroTecH 14 COM 1270 High speed serial ports Chapter 4 Serial port hardware modification This chapter is intended to give you necessary information to modify the COM 1270 default hardware settings to allow you reaching the high speed capability If you want to exceed the RS232 serial speed of 250Kbps you have to remove the driver speed limitation this may be done only for J12 J13 J14 and J11 connectors which have the capability to be bypassed inserting zero ohm resistors packs operating the serial ports in TTL mode to do this hardware modification are needed as described in the following table RS232 factory default J11 U16 installed TTL Remove U16 install CAT16 Resistor Pack RP9 RP10
9. TecH This page is intentionally left blank Index GCOnvVentions PT pm 3 pl r S E 5 Chapter 1 gt Introduction iere oe Ie tee nier det mee Colb re un 6 Exar 16C554 Programmable Baud Rate Generator eene 6 Chapter 2 COM 1270 Serial Connectors interfaces 7 J7 414 Serial Ports in RS232 mode sss rennen 8 J7 J10 Serial ports in RS422 nnn 8 J7 J10 Serial ports in RS485 8 J11 J14 Serial Ports in TTL enne nnne nnne nnn 9 Serial Jue Mm 9 Chapter3 Serial port hardware architecture ccccceceeseeeseeee cece eeeeeeeeeeeeeeeeseseeeaseaneeseeeseseesseeneeseeeens 10 Exar S 1166554 ChipSets HE Ht tia ME ets abico 11 Serial port frequency baud generator 11 GIG OG IG az m 13 Serial port driver section cccccececececceeceeeeeeeeeeeeeaaeeeceeeeeseceaaaeceeeeeeesecccaeceeeeeeeesesenaeaeeeeeesensaaeeeeeeeeeteenaees 13 Chapter4 Serial port hardware modification eeee
10. ncy please refer to the Eurotech S p A Techsupp to obtain a custom configuration After this your serial port is ready to operate at the desired baud rate EuroTecH 20 COM 1270 High speed serial ports Related Documents COM 1270 user s manual http www eurotech it EXAR ST16C554 QUAD UART WITH 16 BYTE FIFO S Cypress CT2292 National Devices ADM21 1 Maxim MAX483 EuroTecH COM 1270 High speed serial ports 21 Technical amp Sales Assistance If you have a technical question please contact the Eurotech Customer Support Service techsupp eurotech it Old and new versions of manuals application notes patches drivers and BIOS can be found at ftp ftp eurotech it If you have a sales question please contact your local Eurotech Sales Representative or the Regional Sales Office for your area Additional and latest information is available at Eurotech website located at http www eurotech it EurolecH
11. nected Not connected Not connected Signal ground ON Oa i o o Z EuroTecH COM 1270 High speed serial ports 9 J11 J14 Serial Ports in TTL mode The following table shows the pinout of the J11 12 13 J14 serial connectors in TTL mode Table 4 J11 12 13 J14 connectors in TTL mode Pin Signal Function In Out DB25 DB9 1 DCD Data Carrier Detect In 8 1 2 DSR Data Set Ready In 6 6 3 RX Receive Data In 3 2 4 RTS Request To Send Out 4 7 5 TX Transmit Data Out 2 3 6 CTS Clear To Send In 5 8 7 DTR Data Terminal Ready Out 20 4 8 RI Ring Indicator In 22 9 9 10 GND Signal Ground 7 5 For detailed information on how to configure the TTL mode for J11 12 13 J14 serial ports please read on Serial settings In order to configure the serial interfaces you have to run the Setup Program For detailed informations please refer to Chapter 5 of the COM 1270 user s manual EurolecH J12 J13 J14 J11 10 COM 1270 High speed serial ports Chapter 3 Serial port hardware architecture To know why hardware modification are necessary to reach high speed serial transmission it is necessary to analize the hardware architecture of the COM 1270 board This section is intended to do this to explain the features of the board with a macro block analisys The following block diagram show the hardware architecture of the serial ports um J7 Clock Svnthetizer
12. o mount R16 The following table report the CY2292 possible output frequency concerning the FSW2 FSW1 and FSWO settings based on the 14 7456MHz FSW2 FSW1 FSWO0 Frequency MHz CPUCLK 23 96160 22 11840 18 43200 16 58800 14 74560 11 05920 9 21600 7 37280 a 0 0 Table 2 CY2292 operating frequency selection The UART frequency is derived by default from CLKB source present on U3 pin 7 output 1 8432 MHz because the JPS2 factory default position is 1 2 the CPUCLK U3 pin 8 signal can be provided making JPS2 on 2 3 position The R14 R15 and R16 factory default are not mounted in this way you reach the FSW2 FSW1 and FSWO 0 logic for an output frequency of 7 37280MHz Sometimes may occur that some custom baud rate couldn t be reached only with modifying the position if the FSW2 0 components and reprogramming the baud rate register in this case you ve to refer directly to the Eurotech S p A for a custom modification changing the Y1 crystal COM 1270 PCB has the capability to install two differents formats of crystal to allow user selecting a wide range of crystal frequencyes The formats are HC49 or U4H SMD with a new reference value and reprogramming the CY2292 Clock synthetizer firmware EuroTecH COM 1270 High speed serial ports 13 Glue Logic The glue logic is based on a Lattice isPLSI1032E which manage various digital logic parts of the COM 1270 board in particular for the serial section manage the acti
13. orpec became Clock Divisorpec Input Frequency 16 Baudrate With the clock frequencyes listed on Table 2 you will obtain the following Clock Divisor rates Frequency MHz Clock Divisorpgc Clock Divisorpec Baud Rate Baud Rate Error CPUCLK Calculated Approximed Approximed 23 96160 2 9952 3 499200 800 22 11840 2 7648 3 460800 39200 18 43200 2 304 2 576000 76000 16 58800 2 0735 2 518375 18375 14 74560 1 8432 2 460800 39200 11 05920 1 3824 1 691200 191200 9 21600 1 152 1 576000 76000 7 37280 0 9216 1 460800 39200 EuroTecH COM 1270 High speed serial ports 19 Note that with an input frequency of 23 96160MHz obtained configuring the R14 R15 and R16 as listed in the following table you reach the minimum difference between the obtained and the wanted baud rate difference of 800baud R14 R15 R16 Mounted Mounted Mounted To select the desired input frequency you ve to modify the R14 R15 and R16 resistor position as listed below referring to Table 2 Frequency is output from U3 pin 8 JPS2 must be on 2 3 position use a cutter to break the standard 1 2 default position Some time a little difference between the wanted and obtained baudrate is tolerated from the circuitry so firt to go on with other modifications try the configuration If you ve stricked limitation on the baud rate frequency you can also change the crystal reference frequency to obtain the exactly baud rate value If you need an exactly baud rate freque
14. ovided for the transmitter and receiver allowing independent TX RX channel control The programmable Baud Rate Generator is capable of accepting an input clock up to 24 MHz as required for supporting a 1 5Mbps data rate An external clock is connected to the XTAL1 pin to clock the internal baud rate generator for standard or custom rates The generator divides the input 16X clock by any divisor from 1 to 216 4 The 16C554D divides the basic crystal or external clock by 16 Further division of this 16X clock provides two table rates to support low and high data rate applications using the same system design Customized Baud Rates can be achieved by selecting the proper divisor values for the MSB and LSB sections of baud rate generator Programming the Baud Rate Generator Registers DLM MSB and DLL LSB provides a user capability for selecting the desired final baud rate EuroTecH COM 1270 High speed serial ports Chapter 2 COM 1270 Serial Connectors interfaces The following image show the layout of the serial ports connectors of the COM 1270 board RS232 only J11 J14 J13 J12 COM5 COM6 COM COMS8 J6 Digital Pd J15 CAN Channels J16 LEDs 2 J1 PC 104 BUS J5 AUI J4 Ethernet E RJ45 D DIETS TTE
15. seseeeeseeseeseesseeeenenneee enne ennt nnn nns 14 Chapter 5 Exar ST16C554 Register List eese nennen nenne nenne nenne na 17 Chapter 6 Pratical example retineret render Mettre ine tn rau asi Re 18 6 COM 1270 High speed serial ports Chapter 1 Introduction The COM 1270 is a PC 104 formfactor board designed for communications it supports eight channels serial ports two CAN ports and one ethernet The first four serial ports can operate in RS232 485 and RS422 mode or be disabled by pair the other ports works only in RS232 mode all the operating modes are software selectable The serial transmission functionalityes of the board are related to the UART 16C554 chipset which is capable to support high speed baudrates The board is configured from factory to operate in a standard baud rate range 50 300 600 1200 2400 4800 9600 19K2 38K4 57K6 and 115K2 software selectable This brief application note is intended to describe how to modify and configure the COM 1270 board to operate with higher baud rates describing which are the hardware settings you ve to realize to make the board high speed capable Exar 16C554 Programmable Baud Rate Generator The serial functionality of the board is based on two Exar 16C554D chipsets which can support up to 921 6Kbps data rate for eight serial ports at his output pins Single baud rate generator is pr
16. vation of the serial drivers reading the EEPROM parameters stored with the SETUP program Note that the driver selection works in pair you can disable enable J7 amp J8 J9 amp J10 J11 amp J14 J13 amp J12 by pair Serial port driver section To fulfil the RS232 RS422 RS485 standard the Exar ST16C554 serial lines have to be converted to the proper phisical signal levels with specific drivers first to be applyed to the external connector The RS232 mode is implemented inserting an ADM211 chipset for the RS485 and RS422 a MAX483 is used For detailed technical information regarding those chipsets please refer to the technical data sheet Looking at the ADM211 and MAX483 data sheet you will be noticed for the following maximum serial trasmission speed listed on the next table Driver Max Data Rate ADM211 230Kbps MAX483 250 Kbps Table 3 Maximum data rate Those are important informations to set the the CY2292 operating frequency selection and Exar ST16C554 baud rate selector because if you select an higher baud rate then the driver may operate as a filter limiting the maximum transmission speed occuring errors on the serial transmission The following table reports the configurability of the eight serial ports of the COM 1270 and listing the high speed capability for each connector Serial Port Mode Selection RS232 RS422 RS485 J7 Yes High Speed limitation High Speed limitation J8 High Speed limitation High
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