.text 
.global _start
_start: 
	/**********LED1点灯**************/
	bl rcc_init
	bl led_init
	bl led1_init
	bl led2_init
	loop:
	bl led_on
	bl delay_1s
	bl led_off
	bl delay_1s
	bl led1_on
	bl delay_1s
	bl led1_off
	bl delay_1s
	bl led2_on
	bl delay_1s
	bl led2_off
	bl delay_1s
	b loop


rcc_init:
ldr r0,=0x50000A28
ldr r1,[r0]
orr r1,#(0x3<<4)
str r1,[r0]
mov pc,lr

led_init:
	ldr r0,=0x50006000
	ldr r1,[r0]
	orr r1,#(1<<20)
	str r1,[r0]
	add r0,#4
	ldr r1,[r0]
	bic r1,#0x400
	str r1,[r0]
	add r0,#4
	mov r1,#0
	str r1,[r0]
	add r0,#4
	mov r1,#0
	str r1,[r0]
	mov pc,lr

led_on:
	ldr r0,=0x50006014
	ldr r1,=0x400
	str r1,[r0]
	mov pc,lr

led_off:	
	ldr r0,=0x50006014
	mov r1,#0
	str r1,[r0]
	mov pc,lr

led2_init:
	ldr r0,=0x50007000
	ldr r1,[r0]
	orr r1,#(1<<20)
	str r1,[r0]
	add r0,#4
	ldr r1,[r0]
	bic r1,#(1<<10)
	str r1,[r0]
	add r0,#4
	ldr r1,[r0]
	bic r1,#(1<<20)
	str r1,[r0]
	add r0,#4
	ldr r1,[r0]
	bic r1,#(0x3<<20)
	str r1,[r0]
	mov pc,lr

led2_on:
	ldr r0,=0x50007014
	ldr r1,[r0]
	orr r1,#(1<<10)
	str r1,[r0]
	mov pc,lr

led2_off:	
	ldr r0,=0x50007014
	ldr r1,[r0]
	bic r1,#(1<<10)
	str r1,[r0]
	mov pc,lr

led1_init:
	ldr r0,=0x50006000
	ldr r1,[r0]
	orr r1,#(1<<16)
	str r1,[r0]
	add r0,#4
	mov r1,#0
	str r1,[r0]
	add r0,#4
	mov r1,#0
	str r1,[r0]
	add r0,#4
	mov r1,#0
	str r1,[r0]
	mov pc,lr


led1_on:
	ldr r0,=0x50006014
	mov r1,#0
	orr r1,r1,#(1<<8)
	str r1,[r0]
	mov pc,lr

led1_off:
	ldr r0,=0x50006014
	ldr r1,[r0]
	bic r1,#(1<<8)
	str r1,[r0]
	mov pc,lr


@ 大概1s的延时函数
delay_1s:
	mov r3, #0x10000000
	mm:
	cmp r3, #0
	subne r3, r3, #1
	bne mm
	mov pc, lr

.end