No SDCC support for PIC18F4620?

MIOS programming (C)
1

Hi all,

I noticed in the SDCC manual, that there is no mention of the 4620 as a supported device :frowning:

18F242 18F248 18F252 18F258 18F442 18F448

18F452 18F458 18F1220 18F2220 18F2550 18F4331

18F4455 18F6520 18F6620 18F6680 18F6720 18F8520

18F8620 18F8680 18F8720

Does anyone know if we can get around this?

2

You can select the PIC18F452 without danger, you only need to adapt the project.lkr file (enhanced RAM/code memory)

Best Regards, Thorsten.

3

Thanks TK :slight_smile:

I suspected this.

Will we need to make new pic18f4620.h and pic18f4620.c files or will the existing 452 files also be OK?

In the linker, am I correct in assuming that locations 0x600 to 0xF7F are available?

I can document this procedure and how to allocate RAM for large arrays once I know these things, thanks!

4

Under normal circumstances you don’t need to create a special .h or .c file for the SFR definitions, the addresses are compatible. Just only the EEADRH register might be important if EEPROM locations >= 0x100 should be accessed, but so long you are not doing this, the pic18f452* files will work fine

Yes, 0x600-0xf7f are available as additional RAM locations. And 0x3000-0xffff is the application code space

Best Regards, Thorsten.

5

Thanks again TK :slight_smile:

For everyone else, I will present full documentation on using the 4620 in your projects shortly. This will relate to both C and ASM projects (but mostly C) and I will also document the procedure for allocating blocks of RAM larger than 256bits.

6

For everyone else, I will present full documentation on using the 4620 in your projects shortly.

Yeah !

So, how did you burn the bootstrap loader ?

7

I said in your projects, not in your core module  ;D heheheheh d’oh!

The burner module on ucapps.de is supposedly the way to go with the 4620’s, but I wouldn’t know from personal experience. My lab is kinda…not ready :wink: One other member of this forum has seen my house and will attest that from the moment you walk in the door, you have to step over little pieces of my lab all the way down the hall, to get to the living room, 1/4 of which is also full of lab bits, and is adjacent to the kitchen which is, you guessed it, covered in pieces of my lab. Then there’s the rest of the house… It’s a nightmare!  ::slight_smile:

8

Hey Bill,

You mentioned in the French forum that you’d had a successful burn, but the Core was not responsive…

Did you edit main.asm and recompile the bootloader from source? The .hex file that you can download for the 452 won’t work.

Edit: Oh yeh, MIOS v1.9b has sneaked onto the download page. Thanks TK :smiley:

I see there is a precompiled 4620 bootloader now, I assume you used that, bill, sorry!.. It was worth a try :wink:

9

There we go, doco.

http://www.midibox.org/dokuwiki/doku.php?id=application_development#using_the_pic18f4620_or_pic18f4520

Feel free to proof read, and correct any errors. It’s 0530 here and I am sleeepy and prone to typing errors and stupid mistakes :wink: