Calling a TABLE by using Indirect Addressing - Electronic Circuits Projects Diagrams Free

Suraj143 · 10th July 2007, 03:36 AM

Hi I want to call a TABLE by using indirect addressing. Now I’m doing like this.

Code:

  
	movlw 	01h
	movwf	11h	;GP register
	movlw	02h
	movwf	12h	;GP register

So if there is more registers I want to write more.

I can clear the GP registers using indirect addressing like below.

Code:

	
	movlw	11h
	movwf	FSR
	clrf	INDF
	incf	FSR,f
	btfss	FSR,7
	goto	$-3
	goto	NEXT

But how I call a TABLE to move all literal values to appropriate registers? (My literal values are in the table)

Thanks a lot

bananasiong · 10th July 2007, 04:10 AM

Code:

	movlw	11h
	movwf	FSR
NEXT	call        table
	movwf    INDF
	incf	FSR,f
	btfss	FSR,7
	goto	NEXT

Suraj143 · 10th July 2007, 04:26 AM

Hi thanks for your reply doesn’t it need a jump value for TABLE?

Another problem if my last GP register is 15h how to detect that.

It means the tables last value must move to this last GP register.
I have only 5 GP registers they are 11h,12h,13h,14h,15h
So after moving last literal value to 15h it must do other work.

How to detect the last 15h register?

Thanks a lot

blueroomelectronics · 10th July 2007, 05:24 AM

Are you trying to read a table from program memory into RAM?

Code:

  table addwf PC,f
       retlw [data] ;is the normal way to read a table on a 14bit PIC core.

you call it with

Code:

    call table ;(where W is the pointer to the table)

Suraj143 · 10th July 2007, 05:37 AM

Ok thanks but how I detect the last value has reached that is 15h?

After moving the last literal value in the table to 15h I want to do other work.

So how can I detect the 15h GP register?

blueroomelectronics · 10th July 2007, 06:24 AM

increment the pointer value at the end of the loop and do a
btfsc pointer,4
goto exit

Suraj143 · 10th July 2007, 06:33 AM

Is this Correct

Code:

	movlw	11h
	movwf	FSR
LOOP	call    table
	movwf   INDF
	incf	FSR,f
	btfss	FSR,4
	goto	LOOP
	goto	EXIT

bananasiong · 10th July 2007, 06:34 AM

Ya, replace

Code:

	btfss	FSR,7
	goto	NEXT

with

Code:

	btfss	FSR,4
	goto	NEXT
	;do other thing here

bananasiong · 10th July 2007, 06:35 AM

You posted it first. That's right.

Suraj143 · 10th July 2007, 06:41 AM

If there is below 8 GP registers its ok. If there is 10 registers how can I detect the last GP register?

Btfss FSR,???

bananasiong · 10th July 2007, 07:46 AM

No, not only 8 general purpose register. Up to 256 general purpose register maximum.
For example, after incf FSR, f

Code:

movf     FSR, w
xorlw     0x1b       ;if you start with 11h and you have 10 GP register,
                         ;the last one will be 1ah
btfss     STATUS, Z
goto      NEXT
goto      exit

Suraj143 · 10th July 2007, 07:52 AM

Wow that’s great man that’s the one I need. So I can put your code into my program.

Thanks a lot

You are excellent

Suraj143 · 10th July 2007, 08:07 AM

So here is the final coding moved table values to GP registers from 11h to 15h.

Code:

	movlw	11h
	movwf	FSR
LOOP	call    table
	movwf   INDF
	incf	FSR,f
	movf    FSR, w
	xorlw   16h     ;test if it is 16h GP register?
	btfss   STATUS, Z
	goto    LOOP
	goto    exit

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10th July 2007, 03:36 AM	(permalink)
Suraj143	Calling a TABLE by using Indirect Addressing Hi I want to call a TABLE by using indirect addressing. Now I’m doing like this. Code: movlw 01h movwf 11h ;GP register movlw 02h movwf 12h ;GP register So if there is more registers I want to write more. I can clear the GP registers using indirect addressing like below. Code: movlw 11h movwf FSR clrf INDF incf FSR,f btfss FSR,7 goto $-3 goto NEXT But how I call a TABLE to move all literal values to appropriate registers? (My literal values are in the table) Thanks a lot Last edited by Suraj143; 10th July 2007 at 03:40 AM.

10th July 2007, 04:10 AM	(permalink)
bananasiong	Code: movlw 11h movwf FSR NEXT call table movwf INDF incf FSR,f btfss FSR,7 goto NEXT __________________ Superman returns..

10th July 2007, 04:26 AM	(permalink)
Suraj143	Hi thanks for your reply doesn’t it need a jump value for TABLE? Another problem if my last GP register is 15h how to detect that. It means the tables last value must move to this last GP register. I have only 5 GP registers they are 11h,12h,13h,14h,15h So after moving last literal value to 15h it must do other work. How to detect the last 15h register? Thanks a lot

10th July 2007, 05:24 AM	(permalink)
blueroomelectronics	Are you trying to read a table from program memory into RAM? Code: table addwf PC,f retlw [data] ;is the normal way to read a table on a 14bit PIC core. you call it with Code: call table ;(where W is the pointer to the table) __________________ Bill Smart Kits build Smart People http://www.blueroomelectronics.com Last edited by blueroomelectronics; 11th July 2007 at 06:32 AM.

10th July 2007, 05:37 AM	(permalink)
Suraj143	Ok thanks but how I detect the last value has reached that is 15h? After moving the last literal value in the table to 15h I want to do other work. So how can I detect the 15h GP register?

10th July 2007, 06:24 AM	(permalink)
blueroomelectronics	increment the pointer value at the end of the loop and do a btfsc pointer,4 goto exit __________________ Bill Smart Kits build Smart People http://www.blueroomelectronics.com

10th July 2007, 06:33 AM	(permalink)
Suraj143	Is this Correct Code: movlw 11h movwf FSR LOOP call table movwf INDF incf FSR,f btfss FSR,4 goto LOOP goto EXIT

10th July 2007, 06:34 AM	(permalink)
bananasiong	Ya, replace Code: btfss FSR,7 goto NEXT with Code: btfss FSR,4 goto NEXT ;do other thing here __________________ Superman returns..

10th July 2007, 06:35 AM	(permalink)
bananasiong	You posted it first. That's right. __________________ Superman returns..

10th July 2007, 06:41 AM	(permalink)
Suraj143	If there is below 8 GP registers its ok. If there is 10 registers how can I detect the last GP register? Btfss FSR,???

10th July 2007, 07:46 AM	(permalink)
bananasiong	No, not only 8 general purpose register. Up to 256 general purpose register maximum. For example, after incf FSR, f Code: movf FSR, w xorlw 0x1b ;if you start with 11h and you have 10 GP register, ;the last one will be 1ah btfss STATUS, Z goto NEXT goto exit __________________ Superman returns..

10th July 2007, 07:52 AM	(permalink)
Suraj143	Wow that’s great man that’s the one I need. So I can put your code into my program. Thanks a lot You are excellent

10th July 2007, 08:07 AM	(permalink)
Suraj143	So here is the final coding moved table values to GP registers from 11h to 15h. Code: movlw 11h movwf FSR LOOP call table movwf INDF incf FSR,f movf FSR, w xorlw 16h ;test if it is 16h GP register? btfss STATUS, Z goto LOOP goto exit