msp430x20x3_clks.s43

MSP430F20xx的汇编程序示例

;*******************************************************************************
;   MSP430F20xx Demo - Basic Clock, Output Buffered SMCLK, ACLK and MCLK/10
;
;   Description: Buffer ACLK on P1.0, default SMCLK(DCO) on P1.4 and MCLK/10 on
;   P1.1.
;   ACLK = LFXT1 = 32768, MCLK = SMCLK = default DCO
;   //* External watch crystal installed on XIN XOUT is required for ACLK *//	
;
;                MSP430F20xx
;             -----------------
;         /|\|              XIN|-
;          | |                 | 32kHz
;          --|RST          XOUT|-
;            |                 |
;            |       P1.4/SMCLK|-->SMCLK = Default DCO
;            |             P1.1|-->MCLK/10 = DCO/10
;            |        P1.0/ACLK|-->ACLK = 32kHz
;
;   M. Buccini / L. Westlund
;   Texas Instruments Inc.
;   October 2005
;   Built with IAR Embedded Workbench Version: 3.40A
;*******************************************************************************
#include  "msp430x20x3.h"
;-------------------------------------------------------------------------------
            ORG     0F800h                  ; Program Reset
;-------------------------------------------------------------------------------
RESET       mov.w   #0280h,SP               ; Initialize stackpointer
StopWDT     mov.w   #WDTPW+WDTHOLD,&WDTCTL  ; Stop WDT
SetupPx     bis.b   #013h,&P1DIR            ; P1.0,1,4 output direction
            bis.b   #011h,&P1SEL            ; P1.0,4 = ACLK,SMCLK
                                            ;
Mainloop    bis.b   #002h,&P1OUT            ; P1.1 = 1
            bic.b   #002h,&P1OUT            ; P1.1 = 0
            jmp     Mainloop                ; Repeat
                                            ;
                                            ;
;-------------------------------------------------------------------------------
;           Interrupt Vectors
;-------------------------------------------------------------------------------
            ORG     0FFFEh                  ; MSP430 RESET Vector
            DW      RESET                   ;
            END