msp430x24x_adc12_01.s43

来自「步进电机驱动程序msp430f247单片机」· S43 代码 · 共 61 行

;*******************************************************************************
;   MSP430x24x Demo - ADC12, Sample A0, Set P1.0 if A0 > 0.5*AVcc
;
;   Description: A single sample is made on A0 with reference to AVcc.
;   Software sets ADC12SC to start sample and conversion - ADC12SC
;   automatically cleared at EOC. ADC12 internal oscillator times sample (16x)
;   and conversion. In Mainloop MSP430 waits in LPM0 to save power until ADC12
;   conversion complete, ADC12_ISR will force exit from LPM0 in Mainloop on
;   reti. If A0 > 0.5*AVcc, P1.0 set, else reset.
;
;                MSP430x24x
;             -----------------
;         /|\|              XIN|-
;          | |                 | 32kHz
;          --|RST          XOUT|-
;            |                 |
;     Vin -->|P6.0/A0      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
SetupADC12  mov.w   #SHT0_2+ADC12ON,&ADC12CTL0 ; Sampling time, ADC12 on
            mov.w   #SHP,&ADC12CTL1         ; Use sampling timer
            mov.w   #01h,&ADC12IE           ; Enable interrupt
            bis.w   #ENC,&ADC12CTL0         ;
            bis.b   #01h,&P6SEL             ; P6.0 ADC option select
            bis.b   #BIT0,&P1DIR             ; P1.0 output
                                            ;
Mainloop    bis.w   #ADC12SC,&ADC12CTL0     ; Start sampling/conversion
            bis.w   #CPUOFF+GIE,SR          ; LPM0, ADC12_ISR will force exit
            jmp     Mainloop                ; Again
                                            ;
;-------------------------------------------------------------------------------
ADC12_ISR;  Exit LPM0 on reti
;-------------------------------------------------------------------------------
            bic.b   #BIT0,&P1OUT             ; P1.0 = 0
            cmp.w   #07FFh,&ADC12MEM0       ; ADC12MEM = A0 > 0.5AVcc?
            jlo     ADC12_ISR_1             ;
            bis.b   #BIT0,&P1OUT             ; P1.0 = 1
ADC12_ISR_1 bic.w   #CPUOFF,0(SP)           ; Exit LPM0 on reti
            reti                            ;
                                            ;
;-------------------------------------------------------------------------------
            COMMON  INTVEC                  ; Interrupt Vectors
;-------------------------------------------------------------------------------
            ORG     ADC12_VECTOR            ; ADC12 Vector
            DW      ADC12_ISR
            ORG     RESET_VECTOR            ; POR, ext. Reset
            DW      RESET
            END