msp430x20x3_nmi.s43

MSP430F20xx的汇编程序示例

;*******************************************************************************
;   MSP430F20xx Demo - Basic Clock, Configure RST/NMI as NMI
;
;   Description: Configure RST/NMI as NMI, hi/lo edge. Flash P1.0  inside of
;   NMI_ISR if NMI occurs. General enable interrupt in status register does
;   not need to be set for NMI. NMIIE does need to be reset, as NMI_ISR
;   automatically clears NMI enable to prevent unintentional stack overflow
;   that could result from, bounce or uncontrolled NMI's.
;   ACLK = n/a, MCLK = SMCLK = Default DCO
;
;                MSP430F20xx
;             -----------------
;         /|\|              XIN|-
;          | |                 |
;          --|RST          XOUT|-
;            |                 |
;
;   M. Buccini / L. Westlund
;   Texas Instruments Inc.
;   October 2005
;   Built with IAR Embedded Workbench Version: 3.40A
;*******************************************************************************
#include  "msp430x20x3.h"
;-------------------------------------------------------------------------------
            ORG     0F800h                  ; Program Reset
;-------------------------------------------------------------------------------
RESET       mov.w   #0280h,SP               ; Initialize stackpointer
SetupWDT    mov.w   #WDTPW+WDTHOLD+WDTNMI+WDTNMIES,&WDTCTL  ; WDT off NMI hi/lo
            bis.b   #01h,&P1DIR             ; P1.0 = output
            bic.b   #01h,&P1OUT             ; P1.0 = reset
            bis.b   #NMIIE,&IE1             ; Enable NMI
                                            ;
Mainloop    jmp     Mainloop                ; Endless Loop
                                            ;
;-------------------------------------------------------------------------------
NMI_ISR   ; Flash P1.0
;-------------------------------------------------------------------------------
            bis.b   #01h,&P1OUT             ; P1.0 = set
Wait        push.w  #020000                 ; Delay value --> TOS
Wait1       dec.w   0(SP)                   ; Decrement TOS
            jnz	    Wait1                   ; Delay over?
            incd.w  SP                      ; Clean up stack
            bic.b   #01h,&P1OUT             ; P1.0 = reset
            bic.b   #NMIIFG,&IFG1           ; reclear NMI flag in case bounce
            bis.b   #NMIIE,&IE1             ; Re-enable NMI interrupt
            reti                            ; Done
                                            ;
;-------------------------------------------------------------------------------
;           Interrupt Vectors
;-------------------------------------------------------------------------------
            ORG     0FFFCh                  ; NMI vector
            DW      NMI_ISR                 ;
            ORG     0FFFEh                  ; MSP430 RESET Vector
            DW      RESET                   ;
            END