#include "msp430.h"                     ; #define controlled include file

        NAME    main                    ; module name

        PUBLIC  main                    ; make the main label vissible
                                        ; outside this module
        ORG     0FFFEh
        DC16    init                    ; set reset vector to 'init' label
        
        ORG     0FFF2h
        DC16    timer

        RSEG    CSTACK                  ; pre-declaration of segment
        RSEG    CODE                    ; place program in 'CODE' segment

init:   MOV     #SFE(CSTACK), SP        ; set up stack

main:   NOP                             ; main program
        MOV     #WDTPW+WDTHOLD, &WDTCTL  ; Stop watchdog timer
        
        ; port 1.0, 1.1 = ausgang
        MOV.B   #BIT0 + BIT1, &P1DIR
        ; port 1 select für timer-output-module
        MOV.B   #BIT1, &P1SEL
        ; port 2.0 = 1
        MOV.B   #BIT0, &P1OUT
        
        ; timer A an
        ; ACLK = 32,768kHz
        ; MAX = 0 .. 65535 = 65536 = 2sek
        MOV.W   #TASSEL0 + MC0, &TACTL
        ; timer A compare 0 benutzen
        ;MOV.W   #CCIE, &TACCTL0        ; für interrupt-betrieb
        MOV.W   #OUTMOD2, &TACCTL0      ; für output-module-betrieb
        MOV.W   #32768-1, &TACCR0       ; compare register setzen (1sek)
        EINT                            ; interrupts aktivieren
        
        
test:   BIS.B   #BIT0, &P1OUT           ; software-led-blinken
        CALL    #warten
        BIC.B   #BIT0, &P1OUT
        CALL    #warten
        JMP     test

warten: MOV.W   #65535, R4              ; 0FFFFh = 65535
        MOV.W   #5, R5
loop:   DEC     R4                      ; R4=0 -> Z=1
        JNZ     loop                    ; wenn Z != 1, springe
        DEC     R5
        JNZ     loop
        RET
        

timer:  PUSH    R4
        PUSH    R5
        INC     R4
        XOR.B   #BIT0, &P1OUT
        POP     R5      ; reihenfolge beachten
        POP     R4
        
        RETI

        
        END