eetest.c

Hitech microchip PIC C18 Compiler

#include <pic18.h>
#include "eedemo.h"
#include <stdio.h>

	/* NOTE: This project shall not function for PIC18Cxxx devices. */

/* fill the EEPROM with initial values */
__EEPROM_DATA(0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07);
__EEPROM_DATA(0x08,0x09,0x0A,0x0B,0x0C,0x0D,0x0E,0x0F);
__EEPROM_DATA(0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17);
__EEPROM_DATA(0x18,0x19,0x1A,0x1B,0x1C,0x1D,0x1E,0x1F);
__EEPROM_DATA(0x20,0x21,0x22,0x23,0x24,0x25,0x26,0x27);
__EEPROM_DATA(0x28,0x29,0x2A,0x2B,0x2C,0x2D,0x2E,0x2F);
__EEPROM_DATA(0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37);
__EEPROM_DATA(0x38,0x39,0x3A,0x3B,0x3C,0x3D,0x3E,0x3F);
__EEPROM_DATA(0x40,0x41,0x42,0x43,0x44,0x45,0x46,0x47);
__EEPROM_DATA(0x48,0x49,0x4A,0x4B,0x4C,0x4D,0x4E,0x4F);
__EEPROM_DATA(0x50,0x51,0x52,0x53,0x54,0x55,0x56,0x57);
__EEPROM_DATA(0x58,0x59,0x5A,0x5B,0x5C,0x5D,0x5E,0x5F);
__EEPROM_DATA(0x60,0x61,0x62,0x63,0x64,0x65,0x66,0x67);
__EEPROM_DATA(0x68,0x69,0x6A,0x6B,0x6C,0x6D,0x6E,0x6F);
__EEPROM_DATA(0x70,0x71,0x72,0x73,0x74,0x75,0x76,0x77);
__EEPROM_DATA(0x78,0x79,0x7A,0x7B,0x7C,0x7D,0x7E,0x7F);

void interrupt ISR(void);

void init(void);
void write(void);
unsigned char read(void);
void putch(unsigned char);

void main(void)
{
	volatile unsigned char data=0;
	unsigned char eeprom_size;
	
	eeprom_size=0xFF;

	init();
	while(1)
	{
		if(TMR1IF)	/* a new action begins each time timer 1 overflows */
		{	
			TMR1IF=0;
			
			LED=(LED^1);	/* toggle LED to indicate a new action has begun */
			
			printf("\rAddress %x was ",EEADR);	/* output the current address */
			if(READ)
			{
				data=read();
				printf("read, value = %x. ",data);	/* output the action */
			}
			else
			{
				EEDATA=BLUE_DIP;
				write();
				printf("written with %x.  ",EEDATA);	/* output the action */
			}
	
			if(EEADR == eeprom_size)	/* after the last EEPROM address */
				EEADR=0;		/* return to the first */
			else
				EEADR++;	/* increment EEPROM address pointer */
		}	
	}
}

void init (void)
{
	T1CON=0x91;	/* Timer 1 is enabled, 1:2 prescale timer */	
	TMR1IE=0;
	TMR1IF=0;

	TRISA=0x10;	/* read/write select switch connect to PORTA4 */
	TRISB=0xFF;	/* PORTB0:3 = RED_DIP1, PORTB5 = pushbutton in */
	TRISC=0x0F;	/*RED_DIP2 switches connect to PORTC */	
	TRISD=0xFF;	/* Data (blue) DIP switches connect to PORTD */

	RBIE=1;	/* PORTB interrupt on change is enabled */
		/* The EEPROM address can be reloaded by */
	RBIF=0;	/* the pushbutton on PORTB5 */
	GIE=1;
	IPEN=0;	/* interrupt priorities are not enabled */

	SPEN=1;	/* enable serial port */
	TXEN=1;	/* serial transmit enabled */
	TXIE=0;	/* not interrupt driven */

	EEADR=0;
}

void write(void)	/* write a byte of data to EEPROM */
{
	GIE=0;		// disable interrupts
	WREN=1;		// enable writes
	EECON2=0x55;	// required sequence for EEPROM update
	EECON2=0xAA;
	WR=1;
	while(WR)continue;
	EEIF=0;
	WREN=0;
	GIE=1;	// re-enable interrupts
}

unsigned char read(void)	/* read a byte of data from EEPROM */
{
	unsigned char eeprom_data;	// in PIC18Fxx2 devices, the data needs
					// to be collected in the next instruction
	GIE=0;				// following RD=1. A temporary variable is
	RD=1;				// created to do this.
	eeprom_data=EEDATA;
	GIE=1;
	return eeprom_data;
}

void putch(unsigned char c)
{
	TXREG=c;
	while(!TXIF)continue;
	TXIF=0;
}

void interrupt ISR(void)	/* interrupt triggered by the pushbuttons */
{
	if((RBIE)&&(RBIF))
	{
		RBIF=0;
		if(ADDRESS_RESET)	/* if the pushbutton is depressed */
			EEADR=RED_DIP;	/* load the red DIP switch to the EEPROM address */
	}
}