msp430x24x_compa_02.s43

步进电机驱动程序msp430f247单片机

;******************************************************************************
;   MSP430x24x Demo - Comparator A, Poll input CA0, CA exchange, result in F249
;
;   Description: The Voltage at pin CA0 (Vcompare) is compared with reference
;   voltage of 0.5*Vcc. LED is toggled when Vcompare crosses the ref voltage.
;
;                 MSP430F249
;             -----------------
;         /|\|                 |
;          | |                 |
;          --|RST      P2.3/CA0|<--Vcompare
;            |                 |
;            |             P1.0|-->CAOUT - 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

            mov.b   #CAEX+CAON+CAREF_2+CARSEL, &CACTL1 ; Enable comp,
                                            ; ref=0.5*Vcc, CA exchange
            mov.b   #P2CA0, &CACTL2         ; Pin to CA0

SetupP1     bis.b   #BIT0,&P1DIR            ; P1.0 = output direction
            bis.b   #BIT0,&P1SEL            ; P1.0 = CAOUT

;-----------------------------------------------------------------------------
            COMMON  INTVEC                  ; Interrupt Vectors
;-----------------------------------------------------------------------------
            ORG     RESET_VECTOR            ; RESET Vector
            DW      RESET                   ;
            END