实验8_思考_adc12_5.s43

MSP-TEST44X 学习板光盘资料及实验说明 本学习板是按照教育大纲

#include          "msp430x44x.h" // Standard Equations
;******************************************************************************
;   MSP-Test44x Demo - ADC12, Using the Internal Reference
;
;   Description: This program will show how to use the internal reference
;                for ADC12.
;
;   This example shows how to use the internal reference of the ADC12.
;   It uses the internal 2.5V reference and performs a single conversion
;   on channel A0. The conversion results are stored in ADC12MEM0 and are 
;   moved to R5 after the conversion is complete. Test by applying a voltage 
;   to channel A0, then setting and running to a break point at "jmp Mainloop". 
;   To view the conversion results, open a register window in C-Spy and view 
;   the contents of R5.
;
;
;                MSP430F449
;              ---------------
;             |               |
;             |      A0 (P6.0)|<---- Vin
;             |               |
;
;

;------------------------------------------------------------------------------ 
main        ORG     01100h                  ; Program Start
;------------------------------------------------------------------------------ 
RESET       mov     #0A00h,SP               ; Initialize stackpointer
StopWDT     mov     #WDTPW+WDTHOLD,&WDTCTL  ; Stop watchdog
            bis.b   #BIT0,&P6SEL            ; Enable A/D channel A0
                                            ;
SetupADC12  mov     #REFON+REF2_5V+ADC12ON+SHT0_2,&ADC12CTL0  
                                            ; turn on 2.5V ref, set samp time
            mov     #SHP,&ADC12CTL1         ; Use sampling timer
            mov.b   #SREF_1,&ADC12MCTL0     ; Vr+=Vref+
                                            ;
            mov     #03600h,R15             ; Delay for needed ref start-up.
L$1         dec     R15                     ; See datasheet for details.
            jnz     L$1                     ;
                                            ;
            bis     #ENC,&ADC12CTL0         ; Enable conversions
                                            ;            
Mainloop    bis     #ADC12SC,&ADC12CTL0     ; Start conversions
testIFG     bit     #BIT0,&ADC12IFG         ; Conversion done?
            jz      testIFG                 ; No, test again
            mov     &ADC12MEM0, R5          ; Move result
            jmp     Mainloop                ; SET BREAKPOINT HERE
                                            ;
;------------------------------------------------------------------------------ 
;           Interrupt Vectors        
;------------------------------------------------------------------------------
            ORG     0FFFEh                  ; MSP430 RESET Vector
            DW      RESET                   ;
            END