;******************************************************************************
;   MSP-FET430P440 Demo - Timer_B, Toggle P5.1, Overflow ISR, 32kHz ACLK
;
;   Description: This program toggles P5.1 using software and Timer_B
;   overflow ISR. In this example an ISR triggers when TB overflows.
;   Inside the TBX_ISR, P5.1 is toggled.  Toggle rate is exactly 0.5Hz.
;   ACLK = LFXT1 = 32768Hz, MCLK = SMCLK = default DCO = 32 x ACLK = 1048576Hz
;   //* An external watch crystal between XIN & XOUT is required for ACLK *//	
;
;                 MSP430F449
;             -----------------
;         /|\|              XIN|-
;          | |                 | 32kHz
;          --|RST          XOUT|-
;            |                 |
;            |             P5.1|-->LED
;
;   M. Buccini
;   Texas Instruments Inc.
;   Feb 2005
;   Built with IAR Embedded Workbench Version: 3.21A
;******************************************************************************
#include  <msp430x44x.h>
;------------------------------------------------------------------------------
            ORG     01100h                  ; Program Start
;------------------------------------------------------------------------------
RESET       mov.w   #0A00h,SP               ; Initialize stackpointer
StopWDT     mov.w   #WDTPW+WDTHOLD,&WDTCTL  ; Stop WDT
SetupFLL    bis.b   #XCAP14PF,&FLL_CTL0     ; Configure load caps
SetupP5     bis.b   #002h,&P5DIR            ; P5.1 output
SetupTB     mov.w   #TBSSEL_1+MC_2+TBIE,&TBCTL  ; ACLK, contmode, interrupt
                                            ;													
Mainloop    bis.w   #LPM3+GIE,SR            ; Enter LPM3, interrupts enabled
            nop                             ; Required only for debugger
                                            ;
;------------------------------------------------------------------------------
TBX_ISR;    Common ISR for TBCCR1-4 and overflow
;------------------------------------------------------------------------------
            add.w   &TBIV,PC                ; Add Timer_B offset vector
            reti                            ; CCR0 - no source
            reti                            ; CCR1
            reti                            ; CCR2
            reti                            ; CCR3
            reti                            ; CCR4
            reti                            ; CCR5
            reti                            ; CCR6
TB_over     xor.b   #002h,&P5OUT            ; Toggle P5.1
            reti                            ; Return from overflow ISR		
                                            ;
;------------------------------------------------------------------------------
;           Interrupt Vectors
;------------------------------------------------------------------------------
            ORG     0FFFEh                  ; MSP430 RESET Vector
            DW      RESET                   ;
            ORG     0FFF8h                  ; Timer_BX Vector
            DW      TBX_ISR                 ;
            END