msp430x24x_wdt_05.s43

来自「步进电机驱动程序msp430f247单片机」· S43 代码 · 共 48 行

;*******************************************************************************
;   MSP430x24x Demo - Reset on Invalid Address fetch, Toggle P1.0
;
;   Description: Toggle P1.0 by xor'ing P1.0 inside of a software loop that
;   ends with TAR loaded with 3FFFh - op-code for "jmp $" This simulates a code
;   error. The MSP430F26x will force a reset because it will not allow a fetch
;   from within the address range of the peripheral memory, as is seen by
;   return to the mainloop and LED flash.
;   ACLK = n/a, MCLK = SMCLK = default DCO ~1.045MHz
;
;                MSP430F249
;             -----------------
;         /|\|              XIN|-
;          | |                 |
;          --|RST          XOUT|-
;            |                 |
;            |             P1.0|-->LED
;
;   B. Nisarga
;   Texas Instruments Inc.
;   September 2007
;   Built with IAR Embedded Workbench Version: 3.42A
;*******************************************************************************
#include "msp430x24x.h"
;-------------------------------------------------------------------------------
            RSEG    CSTACK                  ; Define stack segment
;-------------------------------------------------------------------------------
            RSEG    CODE                    ; Assemble to Flash memory
;-------------------------------------------------------------------------------
RESET       mov.w   #SFE(CSTACK),SP         ; Initialize stackpointer
StopWDT     mov.w   #WDTPW+WDTHOLD,&WDTCTL  ; Stop WDT
SetupP1     bis.b   #001h,&P1DIR            ; P1.0 output
            mov.w   #03FFFh,&TAR            ; "jmp $"
                                            ;
Mainloop    xor.b   #001h,&P1OUT            ; Toggle P1.0
Wait        mov.w   #050000,R15             ; Delay to R15
L1          dec.w   R15                     ; Decrement R15
            jnz     L1                      ; Delay over?
            mov.w   #0170h,PC               ; Invalid fetch
            jmp     Mainloop                ; ** Should never get here **
                                            ;
;-------------------------------------------------------------------------------
            COMMON  INTVEC                  ; Interrupt Vectors
;-------------------------------------------------------------------------------
            ORG     RESET_VECTOR            ; MSP430 RESET Vector
            DW      RESET                   ;
            END