uart

;; uart.asm

;;

;; Copyright 2011-2017 - By Michael Kohn

;; http://www.mikekohn.net/

;; mike@mikekohn.net

;;

;; Serial port (UART) example

.include "msp430x2xx.inc"

RAM equ 0x0200

;  r4 =

;  r5 =

;  r6 =

;  r7 =

;  r8 =

;  r9 =

; r10 =

; r11 =

; r12 =

; r13 =

; r14 =

; r15 =

.org 0xc000

start:

  ;; Turn off watchdog

  mov.w #(WDTPW|WDTHOLD), &WDTCTL

  ;; Interrupts off

  dint

  ;; Setup stack pointer

  mov.w #0x0400, SP

  ;; Set MCLK to 16 MHz with DCO 

  mov.b #(DCO_4), &DCOCTL

  mov.b #RSEL_15, &BCSCTL1

  mov.b #0, &BCSCTL2

  ;; Setup output pins

  ;; P1.2 = Debug LED

  mov.b #0x01, &P1DIR        ; P1.0

  mov.b #1, &P1OUT

  mov.b #6, &P1SEL

  mov.b #6, &P1SEL2

  ;; Setup UART

  mov.b #UCSSEL_2|UCSWRST, &UCA0CTL1

  mov.b #0, &UCA0CTL0

  ;mov.b #0x82, &UCA0BR0

  ;mov.b #0x06, &UCA0BR1

  mov.b #0xf8, &UCA0BR0  ; 9600 baud

  mov.b #0x05, &UCA0BR1

  bic.b #UCSWRST, &UCA0CTL1

  ;; Interrupts on

  eint

  ;; send a bunch of A's

  mov #0, r7

  mov.b #'A', &UCA0TXBUF

main:

  bit.b #UCA0TXIFG, &IFG2

  jz main

  mov.b #'A', &UCA0TXBUF

  inc r7

  jmp main

.org 0xfffe

vectors:

  dw start                 ; Reset