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PIC Asesembly Language - decfsz double loop

PIC Asesembly Language - decfsz double loop

PIC Asesembly Language - decfsz double loop

Hello !

I am working with a PIC 18F microcontroller from Microchip to continuously generate a rectangular signal. The code for the signal itself is at label5.
I need to generate 255*20 pulses of this signal. So basically, I need to repeat the instructions from the first 4 lines at label 5 for 255*20 times. Because I cannot have numbers higher than 2^8, I needed to write the number this way.

CODE --> assembly

label5  BSF portd,5
            call timer1
            BCF portd,5
            call timer2 

In the code below I tried to achieve this behavior. I gave variable1 the value of 255 and I decremented from this value until variable1 was zero, in which case I returned at label2 and restarted the program. Everytime I decremented the variable1 I called label4. A similar things happens at label4. Here I have another variable, variable2, that is also decremented until it hits zero (and here comes the main signal generation program, repeated with each decrement operation), in which case, the program returns.

CODE --> assembly

label2      movlw .255
            movwf variable1

label3      call label4
            decfsz variable1,1
            goto label3

            goto label2

; """"""""""""""

label4      movlw .20
            movwf variable2

label5      BSF portd,5
            call timer1
            BCF portd,5
            call timer2
            decfsz variable2,1
            goto label5


Can someone please tell me if I am on the right track ?

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