Porting PIC16F877 to PIC18F458 problem

xav27 · Guest

Hello everybody,

I'm trying to compile a program written for a PIC16F877 to a PIC18F458.

I only changed #include <18F458.h> and PCWH give me an error :
"Out of ROM, A segment or the program is too large" !

PCWH V3.187
here is a part of my code

#include <18F458.h>
//#include <16F877.h>
#include "register.h"
#fuses HS,NOWDT,NOPUT,NOBROWNOUT,NOPROTECT,NOWRT,NOCPD,NOLVP

#use delay(clock=20000000)
#use rs232(baud=115200, xmit=PIN_C6, rcv=PIN_C7, PARITY=N)
#use fast_io(a)
#use fast_io(c)
...
#define CONST_ADD 0x3F0
...
#ROM CONST_ADD = {
0x00, 0x00, 0x00, 0x00, 0x00, 0x00,...}

//---------- end --------

Can someone give me help
If needed, i can give more code or information

Thanks in advance.

Xavier

ttelmah · Guest

xav27 · Guest

hi ttelmah,

thanks for your help.

: What is 'const_add', and why do you put it in a fixed location?

CONST_ADD is an rom area where i place some data to be changed via a modifed loader.c version.
With a RS232 link to a PC, I can change this values sending hex file(write_eeprom_program() ) it's working fine with a PIC16F877
my loader is located at 0x1C00 to 0x1CFF

I tried to add this line just after #use fast_IO(c); :
#org 0x03F0,0x1BFF {}

but no change, still have the error when compiling.

What should I do ?