gnupic: Re: [gnupic] Error in default link script for pic16f676
Subject:
Re: [gnupic] Error in default link script for pic16f676
From:
"R. Timothy Edwards" ####@####.####
Date:
9 Jun 2007 05:26:56 +0100
Message-Id: <466A2C00.8050005@multigig.com>
Dear David,
>> I found an error in the default link script for the PIC
>> 16F676 chip. The line:
>>
>> SHAREBANK NAME=gpr0 START=0xA0 END=0xDF
>>
>> should be:
>>
>> SHAREBANK NAME=gpr1 START=0xA0 END=0xDF
>>
> <snip>
>> Several other link scripts
>> duplicate the name "gprnobnk", but I'm not sure if this
>> is intentional or not.
> Actually, I think those lines are correct as-is. The SHAREBANK
> directive defines sections of RAM that are shadowed across multiple
> banks of a particular MCU.
I assume you mean that the "gprnobnk" statements are correct as-is,
although I think I have not quite grasped the whole concept of
shared banks (please forgive my ignorance; I'm just now looking at
compiling C code for PICs, where in the past I have written all my
PIC programs in assembler. I'm just getting my brain to adjust to
the statements like BANKSEL that the assembler sticks in that aren't
part of the PIC instruction set). Certainly the duplicate "gpr0"
was a problem in that without it, the linker ran of of data space
on a very simple program, whereas once I changed it, the program
linked, and I was able to download it to the PIC, plug it into the
circuit board, and it ran like a charm.
Admittedly, the 16F676 has a meager amount of memory and is probably
not the best thing to be compiling code for (we're switching to the
more spacious 16F636, but the 676 is what I have on the bench today).
Off-topic:
By the way, is there any plan to write a driver for the USB-based
ICD2 programmer? It's a wonderful little device, and I'd love to
start building boards with the 6-pin modular plug and have in-system
programming capability. But I'm not going to switch to the ICD2
unless I can access it from a Linux box.
Regards,
Tim
+--------------------------------+-------------------------------------+
| Dr. R. Timothy Edwards (Tim) | email: ####@####.#### |
| MultiGiG, Inc. | web: http://www.multigig.com |
| 100 Enterprise Way, Suite A-3 | phone: (831) 621-3283 |
| Scotts Valley, CA 95066 | cell: (240) 401-0616 |
+--------------------------------+-------------------------------------+
