memcpy

[sjharris]

Hello all,

I am starting out with CCS and PIC's. I have got the a point in my program that I need my PIC to learn a few ID's that are read into the PIC via a RS232 line.
When a new ID is to be learned a pin is taken low and the new ID is read on the RS232 line. This ID then must be given a reference (between 1-99) and stored in ROM.

Now I have been playing with the memcpy and read memory address from 0x1000 (as suggested by another user) and got the ff 3f reply. But If I try to put something in there before I read it, for example 11 (ascii) it wont read it back.
{
char ids[10];
int8 rf1[10] = "113A";
}
{
memcpy (0x1000, &rf1[0], 2);
}
{
read_program_memory(0x1000, ids[0], 2);
printf("%x %x %s", ids[0], ids[1], rf1);
}

output from this is

ff 3f 113A

surely it should be

31 31 113A ??

Am I missing something??

Thanks

Steve

[bwgames]

Wouldn't it be easier to use the internal EEPROM? CCS provide commands and examples (EXT_INTEE.C) for this.

e.g. (not checked and it only works if your ID is 8bytes maximum.)

[sjharris]

It would be easier if the PIC i was using had internal EEPROM, I am using the PIC16F77 and has no EEPROM for data.

I am thinking about moving to the PIC16F877 anyways so that will give me user EEPROM.

Thanks for help though.

[Ttelmah]

The reason the program doesn't give the results you expect, is that memcpy, only talks to the RAM, not to the program memory.
You need to write the data, with the write_program_memory command, before you can read it with the read_program_memory command.
Beware, that the write life of the program memory is short. Using EEPROM, is _much_ better, if this data needs to be updated at all frequently. Changing to the 877, or adding an external EEPROM, is a much better solution. Also, if you intend to write to a fixed memory area like this, then you _must_reserve the area, or you will end up overwriting the program...

Best Wishes