 |
 |
| View previous topic :: View next topic |
| Author |
Message |
pe1icq
Joined: 29 Aug 2005
Posts: 12
|
| migrating from Hitech, how to preload EEPROM data? |
 Posted: Mon Aug 29, 2005 4:51 pm |
 |
|
I'm migrating some code that is used with the Hitech PICCompiler.
In an include file there is some code that preloads the EEPROM with some data. It looks like this.
| Code: |
#asm
psect eeprom_data,class=EEDATA,delta=2
db 'A'<<1, 'P'<<1, 'E'<<1, 'R'<<1, 'X'<<1, 'Q'<<1, '0'<<1
db 'N'<<1, 'O'<<1, 'C'<<1, 'A'<<1, 'L'<<1, 'L'<<1, '0'<<1
db 'R'<<1, 'E'<<1, 'L'<<1, 'A'<<1, 'Y'<<1, ' '<<1, '0'<<1
db 'W'<<1, 'I'<<1, 'D'<<1, 'E'<<1, '2'<<1, ' '<<1, ('2'<<1) + 1
#endasm
|
How would I convert this for use with the CCS PCM C Compiler?
Thanks for your help.
//Arno |
|
 |
Mark
Joined: 07 Sep 2003
Posts: 2838
Location: Atlanta, GA
|
|
| Posted: Mon Aug 29, 2005 5:17 pm |
|
|
| Search for #rom in this forum. |
|
|
PCM programmer
Joined: 06 Sep 2003
Posts: 21708
|
|
| Posted: Mon Aug 29, 2005 5:25 pm |
|
|
(But Mark, I already typed this in -- might as well post it).
#include <16F877.H>
#fuses XT, NOWDT, NOPROTECT, BROWNOUT, PUT, NOLVP
#use delay(clock = 4000000)
#rom 0x2100 = {
'A'<< 1, 'P'<< 1, 'E'<< 1, 'R'<< 1, 'X'<< 1, 'Q'<< 1, '0'<< 1, \
'N'<<1, 'O'<<1, 'C'<<1, 'A'<<1, 'L'<<1, 'L'<<1, '0'<<1, \
'R'<<1, 'E'<<1, 'L'<<1, 'A'<<1, 'Y'<<1, ' '<<1, '0'<<1, \
'W'<<1, 'I'<<1, 'D'<<1, 'E'<<1, '2'<<1, ' '<<1, ('2'<<1) + 1
}
//======================================
main(void)
{
while(1);
} |
|
|
MikeValencia
Joined: 04 Aug 2004
Posts: 238
Location: Chicago
|
|
| Posted: Mon Aug 29, 2005 5:32 pm |
|
|
In case you were wondering where he got "0x2100" from, then you have to read the small paragraph in section 2.2 of the following document:
http://ww1.microchip.com/downloads/en/DeviceDoc/39025f.pdf
If you're working with something other than the '877, then you similiarly have to download the corresponding document for that particular chip. "0x2100" is not common to other PICs. |
|
|
Mark
Joined: 07 Sep 2003
Posts: 2838
Location: Atlanta, GA
|
|
| Posted: Mon Aug 29, 2005 7:26 pm |
|
|
| PCM programmer wrote: | (But Mark, I already typed this in -- might as well post it).
#include <16F877.H>
#fuses XT, NOWDT, NOPROTECT, BROWNOUT, PUT, NOLVP
#use delay(clock = 4000000)
#rom 0x2100 = {
'A'<< 1, 'P'<< 1, 'E'<< 1, 'R'<< 1, 'X'<< 1, 'Q'<< 1, '0'<< 1, \
'N'<<1, 'O'<<1, 'C'<<1, 'A'<<1, 'L'<<1, 'L'<<1, '0'<<1, \
'R'<<1, 'E'<<1, 'L'<<1, 'A'<<1, 'Y'<<1, ' '<<1, '0'<<1, \
'W'<<1, 'I'<<1, 'D'<<1, 'E'<<1, '2'<<1, ' '<<1, ('2'<<1) + 1
}
//======================================
main(void)
{
while(1);
} |
Yeah, that's cause you're nicer than I ;) I like for them to do some of the work  |
|
|
pe1icq
Joined: 29 Aug 2005
Posts: 12
|
|
| Posted: Tue Aug 30, 2005 6:45 am |
|
|
Hi Guys,
Thanks for your replies.
I had looked at the #rom directive, but it seemed to me that this could not be used on a 16f628a.
The 16f87x series have eeprom logically mapped to 0x2100 and up.
But the 16f628 has eeprom indirectly addressed via some Special Function Registers.
Any thoughts on that?
Thanks.
//Arno |
|
|
Mark
Joined: 07 Sep 2003
Posts: 2838
Location: Atlanta, GA
|
|
| Posted: Tue Aug 30, 2005 7:12 am |
|
|
It should still work. Did you try it? Look at the other datasheets. They have the same blurb.
Last edited by Mark on Tue Aug 30, 2005 7:13 am; edited 1 time in total |
|
|
pe1icq
Joined: 29 Aug 2005
Posts: 12
|
|
| Posted: Tue Aug 30, 2005 8:34 am |
|
|
I didn't really try yet. Before I do I need to rewrite some of the other Hitech specifics. Hopefully I get to it later tonight.
I'll post the results.
//Arno |
|
|
Ttelmah
Guest
|
|
| Posted: Tue Aug 30, 2005 9:01 am |
|
|
| pe1icq wrote: | Hi Guys,
Thanks for your replies.
I had looked at the #rom directive, but it seemed to me that this could not be used on a 16f628a.
The 16f87x series have eeprom logically mapped to 0x2100 and up.
But the 16f628 has eeprom indirectly addressed via some Special Function Registers.
Any thoughts on that?
Thanks.
//Arno |
The original 16f628 programming datasheet (and those for some of the other similar chips), does not mention this. However the current versions, now specifically say that EEPROM data should be included at address 0x2100. As you say, these chips do not actually map the EEPROM into this area (in fact the whole block from 0x2000 to 0x3FFF, is reserved for the configuration data, which only really occupies the first few bytes), but MicroChip, have logically decided to make the programming spec the same, and require programmers to handle the mapping.
How the EEPROM mapping is done, is a MicroChip decision, not a CCS one. CCS simply allow you to write data to any address using the ROM directive.
Best Wishes |
|
|
pe1icq
Joined: 29 Aug 2005
Posts: 12
|
|
| Posted: Sat Sep 03, 2005 7:33 am |
|
|
The #rom directive was indeed what I needed.
Also for use with the 16f628a I can define eeprom data at addresses 0x2100 and up. And then read them back using read_eeprom() starting at address 0x00.
To all who replied, thanks for your help.
//Arno |
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|
FAQ 
Search
Register
Profile 
Log in to check your private messages 
Log in
