fet140_ta07.s43

TI低功耗MCU用例子

#include  "msp430x14x.h"
;******************************************************************************
;   MSP-FET430P140 Demo - Timer_A Toggle P1.0-3 CCRx Contmode ISR, DCO SMCLK 
;
;   Description; Use timer_A CCRx units and overflow to generate four
;   independent timing intervals. For demonstration, CCR0, CCR1 and CCR2 output
;   units are optionally selected with port pins P1.1, P1.2 and P1.3 in toggle
;   mode. As such, these pins will toggle when respective CCRx registers match
;   the TAR counter. Interrupts are also enabled with all CCRx units,
;   software loads offset to next inderval only - as long as the interval offset
;   is aded to CCRx, toggle rate is generated in hardware. Timer_A overflow ISR 
;   is used to toggle P1.0 with software.  
;   ACLK = n/a, MCLK = SMCLK = TACLK = ~ 800khz DCO 
;   As coded with TACLK ~ 800kHz DCO, toggle rates:
;   P1.1 = CCR0 = 800kHz/(2*200) ~ 2000Hz
;   P1.2 = CCR1 = 800kHz/(2*1000) ~ 400Hz
;   P1.3 = CCR2 = 800kHz/(2*10000) ~ 40Hz
;   P1.0 = overflow = 800kHz/(2*65536) ~ 6Hz
;   Proper use of TAIV interrupt vector generator demonstrated.   
;
;                MSP430F149
;             -----------------
;         /|\|              XIN|-  
;          | |                 |
;          --|RST          XOUT|-
;            |                 |
;            |             P1.1|--> CCR0
;            |             P1.2|--> CCR1
;            |             P1.3|--> CCR2
;            |             P1.0|--> overflow/software
;
;   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+TAIE,&TACTL   ; SMCLK, clear TAR, interrupt
SetupC0     mov.w   #OUTMOD_4 +CCIE,&CCTL0  ; CCR0 toggle, interrupt enabled
SetupC1     mov.w   #OUTMOD_4 +CCIE,&CCTL1  ; CCR1 toggle, interrupt enabled
SetupC2     mov.w   #OUTMOD_4 +CCIE,&CCTL2  ; CCR2 toggle, interrupt enabled
            mov.w   #200,&CCR0              ; 
            mov.w   #1000,&CCR1             ; 
            mov.w   #10000,&CCR2            ; 
SetupP1     bis.b   #00Eh,&P1SEL            ; P1.1 - P1.3 option select
            bis.b   #00Fh,&P1DIR            ; P1.0-3 outputs 
            bis.w   #MC1,&TACTL             ; Start Timer_a in continous mode
            eint                            ; Enable interrupts
                                            ;						  
Mainloop    bis.w   #CPUOFF,SR              ; CPU off
            nop                             ; Required for C-spy
                                            ;
;------------------------------------------------------------------------------ 
TA0_ISR;   
;------------------------------------------------------------------------------ 
            add.w   #200,&CCR0              ; Offset until next interrupt
            reti                            ;		 
                                            ;
;------------------------------------------------------------------------------ 
TAX_ISR;    Common ISR for CCR1-4 and overflow
;------------------------------------------------------------------------------ 
            add.w   &TAIV,PC                ; Add Timer_A offset vector
            reti                            ; CCR0 - no source
            jmp     CCR1_ISR                ; CCR1
            jmp     CCR2_ISR                ; CCR1
            reti                            ; CCR3
            reti                            ; CCR4
TA_over     xor.b   #001h,&P1OUT            ; Toggle P1.0
            reti                            ; Return from overflow ISR		 
                                            ;
CCR1_ISR    add.w   #1000,&CCR1             ; Offset until next interrupt
            reti                            ; Return ISR		 
                                            ;            
CCR2_ISR    add.w   #10000,&CCR2            ; Offset until next interrupt
            reti                            ; Return ISR		 
                                            ;
;------------------------------------------------------------------------------ 
;           Interrupt Vectors Used MSP430x13x/14x          
;------------------------------------------------------------------------------ 
            ORG     0FFFEh                  ; MSP430 RESET Vector
            DW      RESET                   ; 
            ORG     0FFECh                  ; Timer_A0 Vector
            DW      TA0_ISR                 ; 
            ORG     0FFEAh                  ; Timer_AX Vector
            DW      TAX_ISR                 ; 
            END