fet140_ta_pwm04.s43

TI低功耗MCU用例子

#include  "msp430x14x.h"
;******************************************************************************
;   MSP-FET430P140 Demo - Timer_A PWM TA1-2 up-downmode, DCO SMCLK
;
;   Description; This program will generate a two PWM outputs on P1.2/1.3 using
;   Timer_A in an upmode.  The value in CCR0, 128, defines the period/2 and the 
;   values in CCR1 and CCR1 the duty PWM cycles.  Using ~ 800kHz SMCLK as TACLK,
;   the timer period is ~ 320us with a 75% duty cycle on P1.2 and 25% on P1.3. 
;   SMCLK = MCLK = TACLK = default DCO ~ 800kHz. 
;   As coded, the output signals TA1 on P1.2 and TA2 on P1.3 are inverted. 
;
;                MSP430F149
;             -----------------
;         /|\|              XIN|-  
;          | |                 |
;          --|RST          XOUT|-
;            |                 |
;            |             P1.2|--> CCR1 - 75% PWM
;            |             P1.3|--> CCR2 - 25% PWM
;
;   M.Buccini
;   Texas Instruments, Inc
;   January 2002
;******************************************************************************
;----------------------------------------------------------------------------- 
            ORG     01100h                  ; Program Start
;----------------------------------------------------------------------------- 
RESET       mov.w   #0A00h,SP               ; Initialize 'F149 stackpointer
StopWDT     mov.w   #WDTPW+WDTHOLD,&WDTCTL  ; Stop WDT
SetupTA     mov.w   #TASSEL1+TACLR,&TACTL   ; SMCLK, Clear TAR
SetupC0     mov.w   #128,&CCR0              ; PWM Period/2 
SetupC1     mov.w   #OUTMOD_2,&CCTL1        ; CCR1 toggle/reset
            mov.w   #64,&CCR1               ; CCR1 PWM Duty Cycle	  
SetupC2     mov.w   #OUTMOD_6,&CCTL2        ; CCR2 toggle/set
            mov.w   #96,&CCR2               ; CCR2 PWM duty cycle	  
SetupP1     bis.b   #00Ch,&P1DIR            ; P1.2 and P1.3 output
            bis.b   #00Ch,&P1SEL            ; P1.2 and P1.3 TA1/2 otions
            bis.w   #MC1+MC0,&TACTL         ; Start Timer_A in up-down mode
                                            ;					  
Mainloop    bis.w   #CPUOFF,SR              ; CPU off
            nop                             ; Required only for C-spy
                                            ;
;------------------------------------------------------------------------------ 
;           Interrupt Vectors Used MSP430x13x/14x           
;------------------------------------------------------------------------------ 
            ORG     0FFFEh                  ; MSP430 RESET Vector
            DW      RESET                   ; 
            END