PIC18F458 and write_program_eeprom

[xav27]

Hello everybody,
I've read many post before posting my question, and I didn't find the same problem

I have : PIC18F458, CCS V3.187 and ICD-S

I'm using loader.c to update a part of my code (some constantes)
The loader is working fine except when I want to send just a portion of my code.

Here is a little part of my code :

#include <18F458.h>
#fuses HS,NOWDT,NOPROTECT,NOCPD,NOLVP
...
#org 0x3F0,0x410 {} // Reserve some place for CONST
#define CONST 0x3F0
...
#include <loader.c>
...
main()
{
// Print CONST area
addr = CONST_ADD;
for (i=0;i<8;i++)
{
valeur = (int16)read_program_eeprom(addr);
printf("%U ",valeur);
addr+=2;
}

...
load_program();
...
while(true);
}

// Const area to be changed via loader and PC program
#ROM CONST = { 1,0,144,148,4,20,15,89}

//-------END---------

If I send the following hex file, it does'nt works ! (some strange reactions)

:1003F000030000008000800004000A0025001C00AB
:00000001FF
;PIC18F458

This is certainly due to the fact that write_program_eeprom() can't do programming byte per byte (FLASH_ERASE_SIZE = 64) and the loader do a erase_program_eeprom just before writing into program eeprom ?!

Is there a way to make it works ?

Hope I was clear enough.
Thanks in advance for all
Xavier

[PCM programmer]

[xav27]

Hi, PCM programmer

When I post the part of my code I've made little change to be more readable . In fact this is : #define CONST_ADD 0x3F0

I've read in the manual (July 2003) page 90 : (FLASH_ERASE_SIZE)
"For example, if it is 64 bytes then the least significant 6 bits of address is ignored."

If I well understand this mean that loader will erase a block add from 0x3C0 to 0x3FF . So I'll have to program this area ?

What can I do ?

Thanks.

[xav27]

Ni,

Still no answer to my question ! (and did'nt find to do it by myself)

Another way to explain my aim :

Is it possible to send via PC to a PIC using loader only 1 line (hex file format) ???

for example:
:1003F000030000008000800004000A0025001C00AB
:00000001FF

(the second line is necesary to resut the PIC and take change data)

For the moment i can't, and this is probably because the loader routine erase an entire bloc (FLASH_ERASE_SIZE=64)

Is there another way do do it ?

Thank's in advance
Xavier

[Guest]

What you have to do is:

1) Read and store the contents of the entire block (64 bytes) in an array
2) Change the bytes you wich to change
3) Erase the block
4) Reprogram the block from the array