fet140_ta_pwm08.s43

基于IAR Workbench for MSP430 的汇编语言例程

;******************************************************************************
;   MSP-FET430P140 Demo - Timer_A PWM TA1-2 up-down mode, XT2 HF XTAL SMCLK
;
;   Description; This program will generate a two PWM outputs on P1.2/1.3 using
;   Timer_A in an up-down mode.  The value in CCR0, 128, defines the period/2 and the 
;   values in CCR1 and CCR1 the duty PWM cycles.  
;   ACLK = n/a, MCLK = SMCLK = TACLK = XT2 = HF XTAL 
;   //*External watch crystal installed on XT2IN XT2OUT is required for SMCLK*//	  
;
;                MSP430F149
;             -----------------
;         /|\|            XT2IN|-  
;          | |                 | HF XTAL (455k - 8Mhz) 
;          --|RST        XT2OUT|-
;            |                 |
;            |             P1.2|--> CCR1 - 75% PWM
;            |             P1.3|--> CCR2 - 25% PWM
;
;   M.Buccini
;   Texas Instruments, Inc
;   January 2004
;******************************************************************************
#include  "msp430x14x.h"
;----------------------------------------------------------------------------- 
            ORG     01100h                  ; Program Start
;----------------------------------------------------------------------------- 
RESET       mov.w   #0A00h,SP               ; Initialize 'F149 stackpointer
StopWDT     mov.w   #WDTPW+WDTHOLD,&WDTCTL  ; Stop WDT
SetupBC     bic.b   #XT2OFF,&BCSCTL1        ; XT2on
SetupOsc    bic.b   #OFIFG,&IFG1            ; Clear OSC fault flag 
            mov.w   #0FFh,R15               ; R15 = Delay 
SetupOsc1   dec.w   R15                     ; Additional delay to ensure start 
            jnz     SetupOsc1               ;
            bit.b   #OFIFG,&IFG1            ; OSC fault flag set? 
            jnz     SetupOsc                ; OSC Fault, clear flag again 
            bis.b   #SELM_2+SELS,BCSCTL2    ; MCLK = SMCLK = XT2
SetupP1     bis.b   #00Ch,&P1DIR            ; P1.2 and P1.3 output
            bis.b   #00Ch,&P1SEL            ; P1.2 and P1.3 TA1/2 otions
SetupC0     mov.w   #512-1,&CCR0            ; PWM Period/2 
SetupC1     mov.w   #OUTMOD_2,&CCTL1        ; CCR1 toggle/reset
            mov.w   #384,&CCR1              ; CCR1 PWM Duty Cycle	  
SetupC2     mov.w   #OUTMOD_2,&CCTL2        ; CCR2 toggle/reset
            mov.w   #128,&CCR2              ; CCR2 PWM duty cycle	  
SetupTA     mov.w   #TASSEL_2+MC_3,&TACTL   ; SMCLK, updown mode
                                            ;					  
Mainloop    bis.w   #CPUOFF,SR              ; CPU off
            nop                             ; Required only for debugger
                                            ;
;------------------------------------------------------------------------------ 
;           Interrupt Vectors Used MSP430x13x/14x/15x/16x         
;------------------------------------------------------------------------------ 
            ORG     0FFFEh                  ; MSP430 RESET Vector
            DW      RESET                   ; 
            END