msp430x20x3_wdt_01.asm

MSP430F20xx Assembler Examples Code,Composer Essentials Code Examples

;*******************************************************************************
;   MSP430F20xx Demo - WDT, Toggle P1.0, Interval Overflow ISR, DCO SMCLK
;
;   Description: Toggle P1.0 using software timed by the WDT ISR. Toggle rate
;   is approximately 30ms based on default DCO/SMCLK clock source
;   used in this example for the WDT.
;   ACLK = n/a, MCLK = SMCLK = default DCO
;
;		 MSP430F20xx
;             -----------------
;         /|\|              XIN|-
;          | |                 |
;          --|RST          XOUT|-
;            |                 |
;            |             P1.0|-->LED
;
;   P.Thanigai
;   Texas Instruments Inc.
;   May 2007
;   Built with Code Composer Essentials Version: 2.0
;*******************************************************************************
 .cdecls C,LIST,  "msp430x20x3.h"
;------------------------------------------------------------------------------
            .text                           ; Program Start
;------------------------------------------------------------------------------
RESET       mov.w   #0280h,SP               ; Initialize stackpointer
SetupWDT    mov.w   #WDT_MDLY_32,&WDTCTL    ; WDT ~30ms interval timer
            bis.b   #WDTIE,&IE1             ; Enable WDT interrupt
SetupP1     bis.b   #001h,&P1DIR            ; P1.0 output
                                            ;						
Mainloop    bis.w   #CPUOFF+GIE,SR          ; CPU off, enable interrupts
            nop                             ; Required only for debugger
                                            ;
;-------------------------------------------------------------------------------
WDT_ISR;    Toggle P1.0
;-------------------------------------------------------------------------------
            xor.b   #001h,&P1OUT            ; Toggle P1.0
            reti                            ;		
                                            ;
;------------------------------------------------------------------------------
;           Interrupt Vectors
;------------------------------------------------------------------------------
            .sect   ".reset"                ; MSP430 RESET Vector
            .short  RESET                   ;
            .sect   ".int10"                ; WDT Vector
            .short  WDT_ISR                 ;        
            .end