MSP430 – Digital Output

TO TURN ON THE 2 LED (P1.0 & P1.6)

.include "msp430g2x31.inc"
org 0xf800                                                ;SETS THE ADDRESS OF program to
                                                          ;be stored
mov.w #(WDTPW|WDTHOLD),&WDTCTL                           ;DISABLES WATCH DOG TIMER
mov.b #0x41, &P1DIR                                      ;selects the direction of 
                                                          ;the I/O pins
mov.b #0x41, &P1OUT                                      ;Writes logic high value to P1.0 
                                                          ;& P1.6 
loop:
    jmp loop                                            ;Starts the program into infinity 
                                                          ;loop
org 0xfffe                                                ;SETS THE ADDRESS OF Reset vector 
                                                          ;to be stored
dw 0xf800

TO BLINK LED

.include "msp430g2x31.inc"
org 0xf800
mov.w #(WDTPW|WDTHOLD), &WDTCTL
CLR P1OUT
mov.b #0x41, &P1DIR
L1: MOV.W #0xcd40,R4
DELAY:
    DEC R4
    JNZ DELAY
    xor.b #0x41, &P1OUT
    JMP L1
org 0xfffe
dw 0xf800

TOGGLE 2 LEDS

.include "msp430g2x31.inc"
org 0xf800
mov.w #(WDTPW|WDTHOLD), &WDTCTL
CLR P1OUT
mov.b #0x41, &P1DIR
mov.b #0x40, &P1OUT
L1: MOV.W #0xCD40,R4
DELAY:
    DEC R4
    JNZ DELAY
    xor.b #0x41, &P1OUT
    JMP L1
org 0xfffe
dw 0xf800

TOGGLE LEDS USING THE FUNCTION CALLING

.include "msp430g2x31.inc"
org 0xf800
mov.w #(WDTPW|WDTHOLD), &WDTCTL
mov.w #0x280, SP
CLR P1OUT
mov.b #0x41, &P1DIR
mov.b #0x40, &P1OUT
L2: call #L1
    JMP L2
L1: MOV.W #0xCD40,R4
DELAY:
    DEC R4
    JNZ DELAY
    xor.b #0x41, &P1OUT
    ret
org 0xfffe
dw 0xf800

LONG DELAY LOOP

.INCLUDE "msp430x2xx.inc"
ORG 0xf800
MOV #(WDTPW|WDTHOLD), &WDTCTL
MOV #0x280,SP
MOV.B #0x41, &P1DIR
MOV.B #0x41, &P1OUT
LOOP1:
    MOV #65000,R4
    MOV #65000,R5
    CALL #LOOP2
    JMP LOOP1
LOOP2:
    DEC R4
    TST R4
    JNZ LOOP2
LOOP3:
    DEC R5
    TST R5
    JNZ LOOP3
    XOR.B #0x41,&P1OUT
    RET
ORG 0xfffe
DW 0xF800

LED BLINKING USING BIT INSTRUCTION

.INCLUDE "msp430x2xx.inc"
ORG 0xf800
MOV #(WDTPW|WDTHOLD), &WDTCTL
MOV #0x280,SP
MOV.B #0x41, &P1DIR
MOV.B #0, &P1OUT
LOOP2:
    MOV #65000,R4
    CALL #LOOP1
    JMP LOOP2
LOOP1:
    DEC R4
    BIT #0xFFFE,R4               ;SIMPLY "AND"S BETWEEN SRC & DST.
                                 ;RESULT WILL NOT AFFECT SRC & DST.
                                 ;USED FOR BIT TESTING
    JNZ LOOP1
    XOR.B #0x41,&P1OUT
    RET
ORG 0xfffe
DW 0xF800