770 A P P E N D I X E • EPROM Data for a Digital Function Generator

E.2 C Program

This program is also on the accompanying CD in the file

\Student_Files\EPROM\EPROM.C.

*Written by: Ronan Capina and Robert Dueck

*This program is to create a hex file in a specific EPROM record format.

*The EPROM is addressed in blocks of 256 bytes (8 address lines) by an 8 bit

*counter to create a digital image of one of several waveform outputs.

*Two additional address bits select one of four output functions.

*When the EPROM data are run through a D/A Converter, they create an

*analog waveform running at the frequency of the counter divided by 256.

*The waveforms are sine, square, triangle, and sawtooth.

*The record format is as follows. (Spaces are inserted only for clarity.

*The actual record must have NO spaces.)

*

*: 10 0080 00 AF5F67F0602703E0322CFA92007780C3 61

*(:Record Length = 10hex = 16dec)

*(Address = 0080hex; location in EPROM of first data byte in record)

*(Record type = 00 = data)

*(16 data bytes = 32 hex digits)

*(Checksum; Record Length + Address High byte + Address Low byte

*+ Record type + data bytes + Checksum = 00, after discarding carry)

*An END record is also required, having a similar format, except that

*Record Type = 01 = END and there are no data bytes. Checksum is still

*required.

*eg. :00000001FF

*/

#include <stdio.h> #include <stdlib.h> #include <math.h> #include <string.h> #include <conio.h>

void Sawtooth(int); void triangle(int); void Square(int);

int AddrByte(int Addr); int Chksum(int sum); void sine(int);

char *HexString(int value);

char *Hex = HULL; int Ampl;

const double Pi = 3.141592654;

int main(void)

{

FILE *fp;

int Fcn =1, Linenum, sum, Byte, Addr = 0; char Record[256];

clrscr();

*To change the file name, modify the following line to:

*if (!(fp = fopen(“c:\\YourDirectoryName\\YourFile.hex”, “w+t”)))

{

*/

if (!(fp = fopen(“c:\\eprom\\eprom.hex”, “w+t”))) { printf(“Error opening output file.\r\n”); exit(1);

}else

printf(“File opened successfully. \r\n”);

while (Fcn != 5) { /* Create records for 4 functions */

/* Each function has 16 lines of data */ for (Linenum = 1; Linenum <= 16; Linenum++) {

/* Create record and address information */ if (Addr < 16)

sprintf(Record, “:10000%x”, Addr); else

if (Addr < 256)

sprintf(Record, “:1000%x”, Addr);

else

sprintf(Record, “:100%x”, Addr); strcat(Record, “00”);

/* Accumulate sum for calculating checksum */ sum = 16 + AddrByte(Addr);

/* Calculate byte values for selected function */ for (Byte = 1; Byte <= 16; Byte++) {

if (Fcn == 1) sine(Addr % 256);

else if (Fcn == 2) Square(Addr % 256);

else if (Fcn == 3) triangle(Addr % 256);

else

Sawtooth(Addr % 256);

/* Append calculated byte value (amplitude) to the record and update checksum accumulator */

strcat (Record, HexString(Ampl)); sum = sum + Ampl;

Addr++;

}

strcat (Record, HexStrIng(Chksum(sum))); fprintf(fp, “%s\r\n”, Record);

}

Fcn++;

}

fprintf(fp, “:00000001FF\r\n”); fclose(fp);

return(0);

}

772 A P P E N D I X E • EPROM Data for a Digital Function Generator

int AddrByte(int Addr)

{

if (Addr < 256) return Addr;

else

return (((int)(Addr / 256)) + (Addr % 256));

}

int Chksum(int sum)

{

int IntRem = sum % 256; if (IntRem == 0)

return 0;

else

return (256 - IntRem);

}

char *HexString(int value)

{

if (value < 16) {

sprintf(Hex, “0%x”, value); return Hex;

} else if (value > 255) return “FF”;

else {

sprintf(Hex, “%x”, value); return Hex;

}

}

void Sawtooth(int Addr)

{

Ampl = Addr; return;

}

void sine(int Addr)

{

double angle = ((((float)Addr) * 2 * Pi) / 256); Ampl = ((int)((sin(angle) * 128) + 128));

if (Ampl > 255) Ampl = 255; return;

}

void Square(int Addr)

{

if (Addr < 128) Ampl = 255; else

Ampl = 0; return;

}

E.3 Resultant Record File

:10000000808386898C8F9295989C9FA2A5A8ABAE81

:10001000B0B3B6B9BCBFC1C4C7C9CCCED1D3D5D893

:10002000DADCDEE0E2E4E6E8EAECEDEFF0F2F3F54C

:10003000F6F7F8F9FAFBFCFCFDFEFEFFFFFFFFFF01

:10004000FFFFFFFFFFFFFEFEFDFCFCFBFAF9F8F7E8

:10005000F6F5F3F2F0EFEDECEAE8E6E4E2E0DEDC00

:10006000DAD8D5D3D1CECCC9C7C4C1BFBCB9B6B319

:10007000B0AEABA8A5A29F9C9895928F8C898683E1

:100080007F7C797673706D6A6763605D5A575451EF

:100090004F4C494643403E3B383633312E2C2A27BD

:1000A0002523211F1D1B1917151312100F0D0C0AE4

:1000B000090807060504030302010100000000000F

:1000C0000000000000000101020303040506070808

:1000D000090A0C0D0F1012131517191B1D1F2123D0

:1000E00025272A2C2E313336383B3E404346494C97

:1000F0004F5154575A5D6063676A6D707376797CAF

:10010000FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF

:10011000FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEF

:10012000FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFDF

:10013000FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFCF

:10014000FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFBF

:10015000FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFAF

:10016000FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF9F

:10017000FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF8F

:10018000000000000000000000000000000000006F

:10019000000000000000000000000000000000005F

:1001A000000000000000000000000000000000004F

:1001B000000000000000000000000000000000003F

:1001C000000000000000000000000000000000002F

:1001D000000000000000000000000000000000001F

:1001E000000000000000000000000000000000000F

:1001F00000000000000000000000000000000000FF

:1002000080828486888A8C8E90929496989A9C9EFE

:10021000A0A2A4A6A8AAACAEB0B2B4B6B8BABCBEEE

:10022000C0C2C4C6C8CACCCED0D2D4D6D8DADCDEDE

:10023000E0E2E4E6E8EAECEEF0F2F4F6F8FAFCFECE

:10024000FEFCFAF8F6F4F2F0EEECEAE8E6E4E2E0BE

:10025000DEDCDAD8D6D4D2D0CECCCAC8C6C4C2C0AE

:10026000BEBCBAB8B6B4B2B0AEACAAA8A6A4A2A09E

:100270009E9C9A98969492908E8C8A88868482808E

:100280007E7C7A78767472706E6C6A68666462607E

774 A P P E N D I X E • EPROM Data for a Digital Function Generator

:100290005E5C5A58565452504E4C4A48464442406E

:1002A0003E3C3A38363432302E2C2A28262422205E

:1002B0001E1C1A18161412100E0C0A08060402004E

:1002C000020406080A0C0E10121416181A1C1E201E

:1002D000222426282A2C2E30323436383A3C3E400E

:1002E000424446484A4C4E50525456585A5C5E60FE

:1002F000626466686A6C6E70727476787A7C7E80EE

:10030000000102030405060708090A0B0C0D0E0F75

:10031000101112131415161718191A1B1C1D1E1F65

:10032000202122232425262728292A2B2C2D2E2F55

:10033000303132333435363738393A3B3C3D3E3F45

:10034000404142434445464748494A4B4C4D4E4F35

:10035000505152535455565758595A5B5C5D5E5F25

:10036000606162636465666768696A6B6C6D6E6F15

:10037000707172737475767778797A7B7C7D7E7F05

:10038000808182838485868788898A8B8C8D8E8FF5

:10039000909192939495969798999A9B9C9D9E9FE5

:1003A000A0A1A2A3A4A5A6A7A8A9AAABACADAEAFD5

:1003B000B0B1B2B3B4B5B6B7B8B9BABBBCBDBEBFC5

:1003C000C0C1C2C3C4C5C6C7C8C9CACBCCCDCECFB5

:1003D000D0D1D2D3D4D5D6D7D8D9DADBDCDDDEDFA5

:1003E000E0E1E2E3E4E5E6E7E8E9EAEBECEDEEEF95

:1003F000F0F1F2F3F4F5F6F7F8F9FAFBFCFDFEFF85

:00000001FF