fet140_ta08.s43

TI低功耗MCU用例子

#include  "msp430x14x.h"
;******************************************************************************
;   MSP-FET430P140 Demo - Timer_A Toggle P1.0-3 CCRx Contmode ISR, 32kHz ACLK 
;
;   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 = TACLK = 32kHz, MCLK = SMCLK = DCO ~ 800k 
;   As coded and with TACLK = 32768, toggle rates:
;   P1.1 = CCR0 = 32768/(2*4) = 4096Hz
;   P1.2 = CCR1 = 32768/(2*16) = 1024Hz
;   P1.3 = CCR2 = 32768/(2*100) = 163.84Hz
;   P1.0 = overflow = 32768/(2*65536) = 0.25Hz
;   Proper use of TAIV interrupt vector generator demonstrated.   
;   //*An external watch crystal on XIN XOUT is required for ACLK*//	  
;
;                MSP430F149
;             -----------------
;         /|\|              XIN|-  
;          | |                 | 32k
;          --|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   #TASSEL0+TACLR+TAIE,&TACTL   ; ACLK, 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   #4,&CCR0                ; 
            mov.w   #16,&CCR1               ; 
            mov.w   #100,&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   #LPM3,SR                ; Enter LPM3
            nop                             ; Required for C-spy
                                            ;
;------------------------------------------------------------------------------ 
TA0_ISR;   
;------------------------------------------------------------------------------ 
            add.w   #4,&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   #16,&CCR1               ; Offset until next interrupt
            reti                            ; Return ISR		 
                                            ;            
CCR2_ISR    add.w   #100,&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