Timothy,
I have copied below the relevant paragraphs from the MPASM help.
from this I see both use program memory, and for both they give examples 
with hex data.
db - Data Byte.

Reserve program memory words with 8-bit values. Multiple expressions 
continue to fill bytes consecutively until the end of expressions. Should 
there be an odd number of expressions, the last byte will be zero unless in 
a PIC18 code_pack section.

example:

tb1_dta   db   0,0xff    ;Places ff00 in program memory
                         ;location.
   end
for data it sais:

Initialize one or more words of program memory with data. The data may be in 
the form of constants, relocatable or external labels, or expressions of any 
of the above. The data may also consist of ASCII character strings, 
text_string, enclosed in single quotes for one character or double quotes 
for strings. Single character items are placed into the low byte of the 
word, while strings are packed two to a word. If an odd number of characters 
are given in a string, the final byte is zero. On all families except the 
PIC18 device family, the first character is in the most significant byte of 
the word. On the PIC18 device family, the first character is in the least 
significant byte of the word.

and an example is given as:

tb1_dta   data   0xffff,0xaa55   ;Places ffff and aa55 in
                                 ;two consecutive program
                                 ;memory locations.
    end


----- Original Message ----- 
From: "Timothy Weber" <tw@timothyweber.org>
To: "Microcontroller discussion list - Public." <piclist@mit.edu>
Sent: Thursday, September 07, 2006 5:24 PM
Subject: Re: [PIC] defining data in Program Memory


> Lembit Soobik wrote:
>> yes, me again :)
>>
>> This works:
>> my_table
>>  data "Taste 1         " ;0
>>  data "Taste 2         " ;16
>>  data "Taste 3         " ;32
>>  data "Taste 4         " ;48
>>
>> according to MPASM help this should work:
>>
>> PAGA_table
>>   db 0x52, 0x01, 0x51, 0x00, 0x00  ;PA12, GA12, Adr of txt
>>   db 0x52, 0x01, 0x51, 0x01, 0x10  ;PA12, GA12
>>
>> or this:
>> PAGA_table
>>  data 0x52, 0x01, 0x52, 0x03, 0x20 ;PA12, GA12
>>  data 0x52, 0x01, 0x52, 0x04, 0x30 ;PA12, GA12
>>
>>  but in both cases (when I use hex instead of a literal string) I get a
>> runtime error:
>>
>> CORE-E0002: Stack under flow error occurred from instruction at 0x000136
>>
>> question: is it not possible to use hex here?
>
> I don't have the docs here, but is it possible that the "data" directive
> assumes its contents are placed in the data segment, while "db" places
> it directly in the code segment unless you've included a segment
> directive explicitly?
> -- 
> Timothy J. Weber
> http://timothyweber.org
> -- 
> http://www.piclist.com PIC/SX FAQ & list archive
> View/change your membership options at
> http://mailman.mit.edu/mailman/listinfo/piclist
>
>
> -- 
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.1.405 / Virus Database: 268.12.1/440 - Release Date: 06.09.2006
>
> 

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist