Assembly之example

　　Here is a simple example by assembly language. It is based on openMSP430. Very important is to understand "interrupt vectors".

 .global main

 .set   P1OUT, 0x0021
 .set   WDTCTL, 0x0120

 main:

 /* ------------ Disable Watchdog ---------------- */
     MOV #0x5A80, &WDTCTL

 /* ------------ Toggle P1 ------------------------*/
     loop:
         MOV.B #0x00, &P1OUT
         MOV.B #0xff, &P1OUT

     jmp loop

 /* ----------------------------   INTERRUPT VECTORS  --------------- */
 .section .vectors, "a"
 .word loop        ; Interrupt  0 (lowest priority)    <unused>
 .word loop        ; Interrupt  1                      <unused>
 .word loop        ; Interrupt  2                      <unused>
 .word loop        ; Interrupt  3                      <unused>
 .word loop        ; Interrupt  4                      <unused>
 .word loop        ; Interrupt  5                      <unused>
 .word loop        ; Interrupt  6                      <unused>
 .word loop        ; Interrupt  7                      <unused>
 .word loop        ; Interrupt  8                      <unused>
 .word loop        ; Interrupt  9                      <unused>
 .word main        ; Interrupt 10                      Watchdog timer
 .word loop        ; Interrupt 11                      <unused>
 .word loop        ; Interrupt 12                      <unused>
 .word loop        ; Interrupt 13                      <unused>
 .word loop        ; Interrupt 14                      NMI
 .word main          ; Interrupt 15 (highest priority)   RESET