flash.c

Hitech microchip PIC C18 Compiler

/*A sample project file to be used with HI-TIDE, to demonstrate the functionality of the microcontroller's FLASH memory.*/
/*Refer to flash.txt for additional information*/
/*Source code for flash_read and flash_write routines used in this example is found in ~/PIC18/sources/	 directory*/

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

void init(void);

volatile bit RESET;
volatile const unsigned char old_text[]="Insert text here";	/*this is the variable in FLASH where the old text resides*/
unsigned char new_text[]="HI-TECH Software";	/*unlike the old_text this is not a CONST -> stored in data RAM */

far unsigned char * source_ptr = (far unsigned char *)new_text;    /*pointers to data*/
far unsigned char * dest_ptr = (far unsigned char *)old_text;

unsigned char size = sizeof(new_text);						

void main(void){
    init();

	while(1){
		printf("\rcode string reads: %s\n",dest_ptr);	/*print the string from flash*/
		printf("\rwriting to flash...\n");
		flash_write(source_ptr,size,dest_ptr);			/*write to flash memory from data memory */
		printf("\rcode string reads: %s\n",dest_ptr);	/*print the string from flash*/

		while(!RESET);
		RESET=0;
	}
}

void putch(unsigned char c){
	while(!TXIF)continue;
    TXREG=c;					/*transmit a character to Serial IO */
}

void init(void){
    RBIE=1;            /*enable PORTB interrupts to */
    GIEH=1;            /*allow interrupts from PUSH BUTTONS */
    GIEL=1; 

    SPBRG = DIVIDER;       /*enable serial port transmissions */
    TXSTA = (SPEED|0x20);  /*and set up BAUD rate generator*/
    RCSTA = (0x90);														

	TRISB=0xF0;        /*use port B inputs for interface*/
	TRISC=0x80;
	RESET=0;
}