Loops and Branching

Tue Apr 02, 2013 12:26 am

1. Conditional Branching:

Code:: DECFSZ fileReg, d

Decrements file register and skip next instruction if value in file registers reaches 0.

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Code:: BNZ Label

Branch if the value in file register is not zero, it works on zero flag in status register.

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Code:: BZ Label

Branch if the value in file register is zero.

Code:: BNC Label

Branch if no carry, if C flag in status register is zero.

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2. Unconditional Branching:

Code:: GOTO Label

Nested Loops:
Due to the fact that registers in PIC can carry only 8 bits which means it can have numbers only from 0 to 255, and then if we have for loop greater than 255 what should we do? This is the nested loop:

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Comparing Instructions:

Code:: cpfseq f,a ; compare register f with WREG, skip if equal cpfsgt f,a ; compare register f with WREG, skip if greater than cpfslt f,a ; compare register f withWREG, skip if less than decfsz f,d,a ; decrement f, skip if 0 dcfsnz f,d,a ; decrement f, skip if not 0 incfsz f,d,a ; increment f, skip if 0 infsnz f,d,a ; increment f, skip if not 0