Reading and writing to flash

[billy]

The help files on reading and writing to flash are as clear as mud so can anyone help explain a few things.

When the helpfile says that the function write_program_memory( address, dataptr, count ); needs a pointer to a byte what it actually means is that it needs to be passed a variable and that the count value needs to relate to the size of the variable. Am I right?

That would explain some of the examples provided where dataptr is clearly not a pointer, it is a variable, and clearly not an int8, byte or char.

So, assuming I'm right about this, does this mean that if I do the following:

[grasspuddle]

program memory is the executed code, I believe you want the 'write_eeprom()' and 'read_eeprom()' command

see example ex_intee.c

[billy]

Yes, the executed code is stored in flash! On many devices, including the one I'm using (18f4680) the flash is readable and writable by the user code. In my case I have 64kB of flash and my code (almost fully written) uses 16%. this means I can reasonably use 50% (32kB) to store data. Using the EEPROM is not an option as it only has 1024 bytes and I need to store more than 8k of data.

What I wanted was some clarification on how the write_programe_memory(...) functions worked when using different data types like int8, Sint16 and arrays of these variables and arrays of pointers.

About half of the data I want to save to flash are actually pointers so I want to make sure I am saving and retrieving the pointer, not the variable it points to.

Compiler version is 4.041

[Billy]

Ok, I worked it all out and posted some example code showing how to read and write various types of data and pointers to flash - this is now in the code library section of the forum