Post by thread:[PIC]: EEprom initialization on 18F

Hi all, Just trying something that I thought would be simple, but I'm not having much luck. I want to define a null-terminated string in the internal EEPROM of an 18F458, using MPASM. I have tried: org H'F00000' ; Initialize EEPROM Data name de "Bridge", 0 and I get only "Big" in the EEPROM. Apparently it is "word packing" the data, even though the destination is only byte wide. I also tried db and dw, no luck. The following works: org H'F00000' ; Initialize EEPROM Data name data 'B','r','i','d','g','e', 0 But I'd really like to enter a string instead of discrete characters. Any suggestions from those wiser than I? Thanks, Lyle -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email spam_OUTlistservTakeThisOuTmitvma.mit.edu with SET PICList DIGEST in the body

Hi, Lyle Hazelwood wrote: <snip> {Quote hidden}>I want to define a null-terminated string in the >internal EEPROM of an 18F458, using MPASM. > >I have tried: > > > org H'F00000' ; Initialize EEPROM Data >name de "Bridge", 0 > >and I get only "Big" in the EEPROM. >Apparently it is "word packing" the data, >even though the destination is only byte wide. >I also tried db and dw, no luck. > <snip> This seems odd, I've used the following with success: EE_ROMDATA CODE 0xF00000 ; data resides in onchip eerom STRING_ERROR GLOBAL STRING_ERROR DB "Error:",0x00 However, how are you reading the data ? PS: For fixed strings I belive it's better to use the program mem, as it's easy to access them with the TABLAT, and as one can pack two bytes into one program word is fairly efficient DS /Tony -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email .....listservKILLspam@spam@mitvma.mit.edu with SET PICList DIGEST in the body

Lyle, You can also use the notation of '\0' to add the null character (see below). I'm finding out that both methods are synonymous -- they add two null characters (MPLAB v6.22). What does the data EEPROM buffer look like when you load up the Hex file? org H'F00000' ; Initialize EEPROM Data name de "Bridge\0" Regards, Ken Pergola {Original Message removed}

{Quote hidden}>Hi, > >Lyle Hazelwood wrote: ><snip> >>I want to define a null-terminated string in the >>internal EEPROM of an 18F458, using MPASM. >> >>I have tried: >> >> >> org H'F00000' ; Initialize EEPROM Data >>name de "Bridge", 0 >> >>and I get only "Big" in the EEPROM. >>Apparently it is "word packing" the data, >>even though the destination is only byte wide. >>I also tried db and dw, no luck. >> ><snip> > >This seems odd, I've used the following with success: > >EE_ROMDATA CODE 0xF00000 ; data resides in onchip eerom >STRING_ERROR > GLOBAL STRING_ERROR > DB "Error:",0x00 > > >However, how are you reading the data ? > > >PS: For fixed strings I belive it's better to use the program mem, >as it's easy to access them with the TABLAT, and as one can pack two bytes >into one program word is fairly efficient DS > >/Tony How intersting! I tried your code, and it still came up "Big" in the chip. So far, I've been looking into the EEPROM area of my programming software (ICPROG 1.05A). I verified that it is burned into the chip as it shows in the ICPROG window. HOWEVER, when I look into the EEPROM watch window of MPLAB, your method shows correctly and mine shows null bytes between each character. It looks like this may be an ICPROG error I am dealing with. Thanks for the help. I'll be sure to copy this to the author of ICProg. Regarding FLASH vs EEPROM, I am creating "named" nodes on a network, and would prefer to keep the code in flash, but all config info in EEPROM. The config stuff may be changeable later, and by definition node-specific, so I think EEPROM is the best option. Thanks Again, Lyle -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listservKILLspammitvma.mit.edu with SET PICList DIGEST in the body