mptst.asm

* Use 10 MHz crystal frequency. * Use Timer0 for ten millisecond looptime. * Blink "Alive" LED e

 
;
; Just check out MPLAB

  INCLUDE "p18f242.inc"
  
; C Program equivalent
;  #define avalue 100
;  unsigned char i,j,k;
;
;     i = avalue;   /* myvalue = 100 */
;     i = i + 1;   /* i++, i = 101 */
;     j = i;       /* j is 101 */
;     j = j - 1;   /* j--, j is 100 */
;     k = j + i;    /* k = 201 */
;

;  Register Usage
 CBLOCK 0x000	; start at location 0 in data memory
  i, j,k    ; reserve space for three byte variables
 ENDC

avalue equ  D'100'  
  ORG    0
  goto main   ;; reserved space between 0x0-0x1FF for interrupt use

  org 0x0200
main
 
; i = avalue; 
  movlw  avalue   ; w <- 100 
  movwf  i     ; i <- w;

; i = i + 1;
  incf   i,f    ; i <- i + 1

; j = i
  movf   i,w     ; w <- i
  movwf  j      ; j <- w

; j = j - 1;
  decf   j,f    ; j <- j - 1

; k = j + i
  movf   i,w    ; w <- i
  addwf  j,w    ; w <- w + j
  movwf  k    ; k <- w


here
  goto   here	  ; loop forever


  end