.msp430
.include "msp430x2xx.inc"

.org 0xc000
start:
  ;; Turn off watchdog timer.
  mov.w #WDTPW|WDTHOLD, &WDTCTL

  ;; Set P1.0 and P1.6 as outputs.
  mov.b #0x41, &P1DIR

main:
  ;; Initial value for LEDs turns on the P1.0 LED and
  ;; keeps P1.6 turned off.
  mov.w #0x01, r8

  ;; enable  interrupt
  mov.w #TASSEL_2|ID_3|MC_1, &TACTL ; SMCLK, DIV1, COUNT to TACCR0
  mov.w #65000, &TACCR0
  mov.b #CCIE, &TACCTL0
  mov.b #DCO_3, &DCOCTL
  mov.b #RSEL_7, &BCSCTL1

while_1:
  ;; Repeat loop.
  jmp while_1

update_p1:
    ;; Set LEDs to current value of r8 and toggle P1.0 and P1.6.
  mov.b #P1OUT, r8
  xor.b #0x41, r8
  mov.b r8, &P1OUT
    
  reti
  
.org 0xfffe
  dw start             ; set reset vector to 'init' label

.org 0xfff2
  dw update_p1