Svenska ElektronikForumet

Kod: Markera allt

comf 7      ;This instruction inverts the bits in the register specified.
bsf 3,5     ;These instructions set (BSF) the indicated bit in a register.   
decf 70     ;Another common operation is to add or subtract 1 from a register. 
swapf 70,w  ;This peculiar command moves the low 4 bits of the register to the top 4 bits and the top 4 bits of the register to the bottom 4 bits. 
movwf 87    ;The W register is central to most programs. This instruction moves a constant into the W register.


Here are some of the more common registers:
All banks, 0x0 - Indirect register (INDF; see below).
Bank 0/2, 0x1 - Timer 0 register.
Bank 1/3, 0x1 - Option register.
All banks, 0x2 - Low 8 bits of program counter (current program location).
All banks, 0x3 - STATUS register. Contains flags that tell you if the last operation resulted in a zero result or generated a carry. Also contains the RP bits.
All banks, 0x4 - Indirect pointer (FSR; see below).
Bank 0, 0x5 - PORT A data bits.
Bank 1, 0x5 - PORT A direction bits.
Bank 0/2, 0x6 - PORT B data bits.
Bank 1/3, 0x6 - PORT B direction bits.
Bank 0, 0x7 - PORT C data bits.
Bank 1, 0x7 - PORT C direction bits.
All banks, 0xA - PCLATH (used to load high bits of program counter).
All banks, 0xB - Interrupt control register.

Kod: Markera allt

comf   portc        ; byt 0 <-> 1 på PORTC (eller TRISC om bank 1/3 är vald).
bsf    status, RP0  ; byt till bank 1/3
decf   70           ; Minska värdet på adress h'70' (i non-banked memory)
swapf  70, w        ; Swap high/low nibble och lägg resultatet i W
movwf  87           ; Uppdatera TRISC med värdet i W