-----Original Message-----
From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On Behalf Of
Phil Cross
Sent: Friday, November 25, 2005 10:19 AM
To: piclist@mit.edu
Subject: [PIC] : 18F452 table addresses

I'm a beginner, trying to use an 18F452 as a controller. I have a problem, 
although it may be my ignorance that prevents me seeing the solution. I read

around, but can't find how to do it.

I am using MPASM 7.2

I want to define a number of what I call "canned" messages in flash memory, 
thus:

message1
     dw    "String1",0
message2
     dw    "String2",0
message3
     dw    "String3",0
etc.

(I use NULL as string terminator, and ensure even number of bytes in each 
message.)

I want to be able to load TBLPTR with the label address of (say) message2, 
and then use the 18F452
TBLRD + instruction to step through and read the message bytes, until I 
reach NULL, while transmitting them on RS232.

What I don't understand is how I get the addresses of message1, message2 
etc. in order to load them into TBLPTR. I need the equivalent of 'C' '&' 
deferencing.

Is there such a thing, please? I don't want to have to ORG every message - I

want the compiler to take care of its location.

Regards, Phil.


	CLRF	TBLPTRU	; Set the Upper table pointer to 0x00.
	MOVLW	HIGH ARG1	; Fetch the HIGH address of the table.
(message1)
	MOVWF	TBLPTRH	; Set the High table pointer.
	MOVLW	LOW ARG1	; Fetch the LOW address of the table.
(message1)
	MOVWF	TBLPTRL	; Set the Low table pointer.

-- 


  *
  |  __O    Thomas C. Sefranek  tcs@cmcorp.com
  |_-\<,_   Amateur Radio Operator: WA1RHP
  (*)/ (*)  Bicycle mobile on 145.41MHz PL74.4
 
ARRL Instructor, Technical Specialist, VE Contact.
http://hamradio.cmcorp.com/inventory/Inventory.html
http://www.harvardrepeater.org


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