buzzer.s

来自「该驱动程序是针对2410开发板的LED灯的驱动」· S 代码 · 共 58 行

/*
 * Name : buzzer.s
 * Disc : buzzer on and off.
 * 2007-08-02 by Qingmin Liu
 */

@ register address
.equ WTCON,	0x53000000
.equ GPBCON,	0x56000010

@ offset value
.equ oGPBDAT,	0x04
.equ oGPBUP,	0x08

@ macro defination
.macro BUZZER
        mov r1, #0x1
        str r1, [r0, #oGPBDAT]
        bl delay
	mov r1, #0x0
	str r1, [r0, #oGPBDAT]
	bl delay
.endm

.text
.global _start

_start:
	@ disable watch dog timer
	mov r0, #WTCON
	mov r1, #0x0
	str r1, [r0]

	@ setup the GPBCON
	ldr r0, =GPBCON
	mov r1, #0x01
	str r1, [r0]
1:
	BUZZER
	b 1b

stop:
	b stop

@
@ SUB Routine
@

delay:
	mov r2, #0x30000
1:
	subs r2, r2, #0x1
	bne 1b

	mov pc, lr

.end