MSP430-assembly language part-1-DIGITAL IO

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By Jackson Taylor

HERE I AM USING NAKEN430ASM COMPILER AND MSP430G2231 CONTROLLER
         
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  output on the corresponding I/O pin   
loop:
     jmp loop            ;runs 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
digital input using the P1.3 (pull down resistor required)
      .include “msp430g2x31.inc”
      org 0xf800                           
      mov.w #(WDTPW|WDTHOLD), &WDTCTL
      CLR.B P1OUT
      CLR R5  
      mov.b #0x41, &P1DIR 
L1:   MOV.b &P1IN,  r5
      AND.b #0x8,r5
      tst r5
      JZ L1
      mov.b #0x41, &P1OUT 
L3:   jmp L3
      org 0xfffe
      dw 0xf800 
Please see more @ 
http://jimmyjosep.blogspot.in/2013/12/msp430-assembly-language-part-1.html
digital input using the P1.3 (pull down resistor required)
      .include “msp430g2x31.inc”
      org 0xf800                           
      mov.w #(WDTPW|WDTHOLD), &WDTCTL
      CLR.B P1OUT
      CLR R5  
      mov.b #0x41, &P1DIR 
L1:   MOV.b &P1IN,  r5
      AND.b #0x8,r5
      tst r5
      JZ L1
      mov.b #0x41, &P1OUT 
L3:   jmp L3
      org 0xfffe
      dw 0xf800 
Please see more @ 
http://jimmyjosep.blogspot.in/2013/12/msp430-assembly-language-part-1.html