Re: Using external EEprom - need a little guidance
Hi Scampy;
Here is a code i do some time go to interface a 93c46 using both MSSP and Shift. Hope ot will be useful to you;
Code:'**************************************************************** '* Name : 93C46N EEPROM + MSSP * '* Author : [GADELHAS] * '* Notice : Copyright (c) 2012 * '* : All Rights Reserved * '* Date : 08-02-2012 * '* Version : 1.0 * '* Notes : * '* : EASYPICV6 + PIC16F887 + 93C46N - FARCHILD * '**************************************************************** ' CONFIGS ' ================================================================ @ __CONFIG _CONFIG1, _HS_OSC & _WDT_OFF & _PWRTE_OFF & _MCLRE_ON & _CP_OFF & _BOR_OFF & _DEBUG_OFF & _LVP_OFF & _FCMEN_ON & _IESO_OFF @ __CONFIG _CONFIG2, _WRT_OFF & _BOR40V ' DEFINES & INCLUDES ' ================================================================ DEFINE OSC 8 ' REGISTERS AND PINOUT ( 1 = IN; 0 = OUT ) ' ================================================================ '76543210 '76543210 TRISA = %00000000: PORTA = %00000000 TRISB = %00000000: PORTB = %00000000 TRISC = %00010000: PORTC = %00000000 TRISD = %00000000: PORTD = %00000000 TRISE = %00000000: PORTE = %00000000 ADCON0 = %00000000 ADCON1 = %00000000 ANSEL = %00000000 ANSELH = %00000000 CM1CON0 = %00000000 CM2CON0 = %00000000 SSPSTAT = %00000000 'Configures the SPI Module ( Read DataSheet ) SSPCON = %00110001 'Configures the SPI Module ( Read DataSheet ) ' ALIAS & MODIFIERS ' ================================================================ CS VAR PORTC.1 'Pin 1 of the 93C46N - PDIP CASE ( CS ) CLK VAR PORTC.3 'Pin 2 of the 93C46N - PDIP CASE ( SK ) SDI VAR PORTC.4 'Pin 4 of the 93C46N - PDIP CASE ( DO ) SDO VAR PORTC.5 'Pin 3 of the 93C46N - PDIP CASE ( DI ) ' VARIABLES & COSTANTS ' ================================================================ ADDRESS VAR BYTE 'Address position to read or write BT0 VAR BYTE 'Byte 0 to read or write BT1 VAR BYTE 'Byte 1 to read or write I VAR BYTE ' DEFINES ' ==================================================================== DEFINE LCD_DREG PORTB ' LCD Data bits on PORTB DEFINE LCD_DBIT 0 ' PORTB starting address DEFINE LCD_RSREG PORTB ' LCD RS bit on PORTB DEFINE LCD_RSBIT 4 ' LCD RS bit address DEFINE LCD_EREG PORTB ' LCD E bit on PORTB DEFINE LCD_EBIT 5 ' LCD E bit address DEFINE LCD_BITS 4 ' LCD in 4-bit mode DEFINE LCD_LINES 2 ' LCD has 2 rows DEFINE LCD_COMMANDUS 2000 ' Set command delay time in us DEFINE LCD_DATAUS 50 ' Set data delay time in us DEFINE DEBUG_REG PORTC DEFINE DEBUG_BIT 6 DEFINE DEBUG_BAUD 19200 DEFINE DEBUG_MODE 0 ' PROGRAM INIT ' ================================================================ '0123456789012345 LCDOUT $FE, 1, " 93C46 EEPROM " PAUSE 2000 DEBUG "Start", 13,10,13,10 ' MAIN LOOP ' ================================================================ MAIN: FOR I = 0 TO 63 GOSUB READ2BYTES LCDOUT $FE, 1, "Iteracao: ", DEC I LCDOUT $FE,$C0,"BT0:", HEX BT0, " - BT1:", HEX BT1 DEBUG "Iteracao: ", DEC I," - ", HEX BT0,HEX BT1,13,10 NEXT STOP GOTO MAIN ' SUB - ROTINES ' ================================================================ WRITE2BYTES: CS=1 'Enable Device SSPBUF = $1 'Start Bit SSPBUF = $30 'Command to Write CS=0 'Disable Device CS=1 'Select Device SSPBUF = $1 'Start Bit WHILE SSPSTAT.0=0:WEND 'Wait for the BF flag to be Set SSPBUF = $40 | ADDRESS '01000000 Ored with ADDRESS WHILE SSPSTAT.0=0:WEND 'Wait for the BF flag to be Set SSPBUF = BT0 'Data 00 WHILE SSPSTAT.0=0:WEND 'Wait for the BF flag to be Set SSPBUF = BT1 'Data 01 WHILE SSPSTAT.0=0:WEND 'Wait for the BF flag to be Set CS=0 'Disable Device PAUSE 5 'Insure that you don't work you the device for 5ms RETURN READ2BYTES: CS=1 'Enable Device SSPBUF = $1 'Start Bit WHILE SSPSTAT.0=0:WEND 'Wait for the BF flag to be Set SSPBUF = $80 | ADDRESS '10000000 Ored with ADDRESS WHILE SSPSTAT.0=0:WEND 'Wait for the BF flag to be Set SSPCON.4=0 'Change Signal Clock "DataSheet of the PIC" SSPBUF = $0 'Send Something WHILE SSPSTAT.0=0:WEND 'Wait for the BF flag to be Set BT0=SSPBUF 'Read the SSPBUF to the BT0 Variable SSPBUF = $0 'Send Something WHILE SSPSTAT.0=0:WEND 'Wait for the BF flag to be Set BT1=SSPBUF 'Read the SSPBUF to the BT1 Variable CS=0 'Disable Device SSPCON.4=1 'Change the clock to initial state PAUSE 5 'Insure that you don't work you the device for 5ms RETURN ERASEALL: CS = 1 'Enable Device SSPBUF = $1 'Start Bit WHILE SSPSTAT.0=0:WEND 'Wait for the BF flag to be Set SSPBUF = $20 'Command to Erase ALL WHILE SSPSTAT.0=0:WEND 'Wait for the BF flag to be Set CS = 0 'Disable Device PAUSE 5 'Insure that you don't work you the device for 5ms RETURN WRITEALL: CS = 1 'Enable Device SSPBUF = $1 'Start Bit WHILE SSPSTAT.0=0:WEND 'Wait for the BF flag to be Set SSPBUF = $10 'Command to Erase ALL WHILE SSPSTAT.0=0:WEND 'Wait for the BF flag to be Set SSPBUF = BT0 'Data Pattern 00 WHILE SSPSTAT.0=0:WEND 'Wait for the BF flag to be Set SSPBUF = BT1 'Data Pattern 01 WHILE SSPSTAT.0=0:WEND 'Wait for the BF flag to be Set CS = 0 'Disable Device PAUSE 5 'Insure that you don't work you the device for 5ms RETURN END
Code:'**************************************************************** '* Name : 93C46N EEPROM * '* Author : [GADELHAS] * '* Notice : Copyright (c) 2012 * '* : All Rights Reserved * '* Date : 08-02-2012 * '* Version : 1.0 * '* Notes : * '* : EASYPICV6 + PIC16F887 + 93C46N - FARCHILD * '**************************************************************** ' CONFIGS ' ================================================================ @ __CONFIG _CONFIG1, _HS_OSC & _WDT_OFF & _PWRTE_OFF & _MCLRE_ON & _CP_OFF & _BOR_OFF & _DEBUG_OFF & _LVP_OFF & _FCMEN_ON & _IESO_OFF @ __CONFIG _CONFIG2, _WRT_OFF & _BOR40V ' DEFINES & INCLUDES ' ================================================================ DEFINE OSC 8 ' REGISTERS AND PINOUT ( 1 = IN; 0 = OUT ) ' ================================================================ '76543210 '76543210 TRISA = %00000000: PORTA = %00000000 TRISB = %00000000: PORTB = %00000000 TRISC = %10101101: PORTC = %00000000 TRISD = %00000000: PORTD = %00000000 TRISE = %00000000: PORTE = %00000000 ADCON0 = %00000000 ADCON1 = %00000000 ANSEL = %00000000 ANSELH = %00000000 CM1CON0 = %00000000 CM2CON0 = %00000000 ' ALIAS & MODIFIERS ' ================================================================ CS VAR PORTC.1 'Pin 1 of the 93C46N - PDIP CASE ( CS ) CLK VAR PORTC.3 'Pin 2 of the 93C46N - PDIP CASE ( SK ) SDI VAR PORTC.4 'Pin 4 of the 93C46N - PDIP CASE ( DO ) SDO VAR PORTC.5 'Pin 3 of the 93C46N - PDIP CASE ( DI ) ' VARIABLES & COSTANTS ' ================================================================ ADDRESS VAR BYTE 'Address position to read or write BT0 VAR BYTE 'Byte 0 to read or write BT1 VAR BYTE 'Byte 1 to read or write I VAR BYTE ' DEFINES ' ==================================================================== DEFINE LCD_DREG PORTB ' LCD Data bits on PORTB DEFINE LCD_DBIT 0 ' PORTB starting address DEFINE LCD_RSREG PORTB ' LCD RS bit on PORTB DEFINE LCD_RSBIT 4 ' LCD RS bit address DEFINE LCD_EREG PORTB ' LCD E bit on PORTB DEFINE LCD_EBIT 5 ' LCD E bit address DEFINE LCD_BITS 4 ' LCD in 4-bit mode DEFINE LCD_LINES 2 ' LCD has 2 rows DEFINE LCD_COMMANDUS 2000 ' Set command delay time in us DEFINE LCD_DATAUS 50 ' Set data delay time in us DEFINE DEBUG_REG PORTC DEFINE DEBUG_BIT 6 DEFINE DEBUG_BAUD 19200 DEFINE DEBUG_MODE 0 ' PROGRAM INIT ' ================================================================ '0123456789012345 LCDOUT $FE, 1, " 93C46 EEPROM " PAUSE 2000 DEBUG "Start",13,10,13,10 ' MAIN LOOP ' ================================================================ MAIN: FOR I = 0 TO 63 GOSUB READ2BYTES LCDOUT $FE, 1, "Iteracao: ", DEC I LCDOUT $FE,$C0,"BT0:", HEX BT0, " - BT1:", HEX BT1 DEBUG "Iteracao: ", DEC I," - ", HEX BT0,HEX BT1,13,10 NEXT STOP GOTO MAIN ' SUB - ROTINES ' ================================================================ WRITE2BYTES: CS = 1 SHIFTOUT SDO,CLK,1,[%10011,0\4] 'Enable write PAUSE 5 CS = 0 CS = 1 SHIFTOUT SDO, CLK, 1, [%101\3,ADDRESS\6,BT0,BT1] 'Two bytes at a time PAUSE 5 CS = 0 RETURN READ2BYTES: CS=1 SHIFTOUT SDO,CLK,1,[%110\3,ADDRESS\6] SHIFTIN SDI,CLK,2,[BT0,BT1] 'Two bytes at a time PAUSE 5 CS=0 RETURN ERASEALL: CS = 1 SHIFTOUT SDO,CLK,1,[%10010,0\4] PAUSE 5 CS = 0 RETURN WRITEALL: CS = 1 SHIFTOUT SDO,CLK,1,[%10001,0\4,BT0,BT1] 'Two bytes data pattern PAUSE 5 CS = 0 RETURN END
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