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Multiplication on MPLAB - PIC16F84A

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dannyelloko20

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I need some help on how to multiply a hex value five times using asm code. Im stuck and cant start my project.

Thanks in advance.
 

dannyelloko20

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Good stuff! However im dealing with a PIC16F84A and the instructions on the link above are different. Thanks though i can actually use the examples they have to get a better idea as to how the logic works.
 

betwixt

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??? those ARE instructions the 16F84A understands. MPLAB creates aliases for the 'skp' instructions, they are mentioned in the MPLAB help files and earlier in the web link.

Trick: if you know the RESULT is going to fit in 8 bits (no greater than 255), you can do it in fewer instructions:

1. enter with the value in W.
2. copy W to a memory location.
3. shift it to the left (now holds 2 * value)
4. shift it to the left (now holds 4 * value)
5. add W to the memory location.

Depending on whether you set W or the memory as the destination, it now holds (value + (value * 4)) = value * 5.

Brian.
 

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