EEPROM Address

[jecottrell]

18F2620
3.249

To address the EEPROM in the read and write_eeprom functions do I just use the 0x00 to 0x3FF addresses? It's been a while since I've done this and in my research I've found some conflicting info.

EDIT: Just thought to look at the CCS manual, it gives the address as an 8bit number. Kind of tough to address 1024 locations with 8bits?

EDIT2: Looks like they changed the verbiage in later manuals, 8 OR 16bit value depending on part.

Looks like I've got my answer. Just use 0x00 to 0x3FF. Anyone want to confirm?

Thanks,

John

[newguy]

0x000 to 0x3ff is correct. The exception is when you want to preload the EEPROM with data at programming time.

[jecottrell]

Thanks.

I had seen that and that was part of the confusion. I also had some old code that used the wrong approach but worked.

John

[jecottrell]

Now I'm trying to program some EEPROM locations prior to run-time. I want to make sure this is the right address. The Programming Spec says:

[Ttelmah]

It is correct, but the easiest/safest way, is to use the compiler!...

[newguy]

Also be careful with the size of the data written to the EEPROM. I remember a project where I was expecting bytes out of the preprogrammed EEPROM but the compiler loaded it as if the data was int16's.

[jecottrell]

Thanks for the info. I had seen the getenv in another post and had assumed it was v4 unique. I'll look and see if it is v3 friendly and use it.

I just spent all morning trying to find an addressing problem. I was using int8s in some calculations for address offsets. Only took me about 5 hours to figure out I had to cast them to int16s.

[ckielstra]

[jecottrell]