ARM--LED灯点亮

 LED1,LED2,LED3亮灯

 .text 
 .global _start
 _start: 
	/**********LED1点灯--->PE10**************/

 /*初始化RCC章节*/
 @通过RCC_MP_AHB4ENSETR寄存器,使能GPIOs组控制器	0x500000A28[4] = 1
 RCC_INIT:
	@ E组和F组一起使能
	ldr r0,=0x50000A28		
	ldr r1,[r0]
	orr r1,r1,#(0x3 << 4)
	str r1,[r0]

 @输出，推挽，速率，上下拉
 LED1_INIT:
	@通过GPIOx_MODER寄存器设置PE10引脚的模式为输出 0x50006000[21:20] = 01
	ldr r0,=0x50006000
	ldr r1,[r0]
	bic r1,r1,#(0x3 << 20)
	orr r1,r1,#(0x1 << 20)
	str r1,[r0]

	@ PF10
	ldr r0,=0x50007000
	ldr r1,[r0]
	bic r1,r1,#(0x3 << 20)
	orr r1,r1,#(0x1 << 20)
	str r1,[r0]

	@ PE8
	ldr r0,=0x50006000
	ldr r1,[r0]
	bic r1,r1,#(0x3 << 16)
	orr r1,r1,#(0x1 << 16)
	str r1,[r0]
	
	@通过GPIOx_OTYPER寄存器设置PE10引脚为推挽输出类型 0x50006004[10] = 0
	ldr r0,=0x50006004
	ldr r1,[r0]
	and r1,r1,#(0x0 << 10)
	str r1,[r0]

	@ PF10
	ldr r0,=0x50007004
	ldr r1,[r0]
	and r1,r1,#(0x0 << 10)
	str r1,[r0]

	@ PE8
	ldr r0,=0x50006004
	ldr r1,[r0]
	and r1,r1,#(0x0 << 8)
	str r1,[r0]

	@通过GPIOx_OSPEEDR寄存器设置PE10引脚为低速率输出 0x50006004[21:20] = 00
	ldr r0,=0x50006008
	ldr r1,[r0]
	bic r1,r1,#(0x3 << 20)
	str r1,[r0]

	@ PF10
	ldr r0,=0x50007008
	ldr r1,[r0]
	bic r1,r1,#(0x3 << 20)
	str r1,[r0]

	@ PE8
	ldr r0,=0x50006008
	ldr r1,[r0]
	bic r1,r1,#(0x3 << 16)
	str r1,[r0]

	@通过GPIOx_PUPDR寄存器设置PE10引脚无上下拉 0x5000600C[21:20] = 00
	ldr r0,=0x5000600C
	ldr r1,[r0]
	bic r1,r1,#(0x3 << 20)
	str r1,[r0]

	@ PF10
	ldr r0,=0x5000700C
	ldr r1,[r0]
	bic r1,r1,#(0x3 << 20)
	str r1,[r0]

	@ PE8
	ldr r0,=0x5000600C
	ldr r1,[r0]
	bic r1,r1,#(0x3 << 16)
	str r1,[r0]


 loop:
	bl LED1_ON
	bl delay_1s
	bl LED1_OFF
	bl delay_1s
	bl LED2_ON
	bl delay_1s
	bl LED2_OFF
	bl delay_1s
	bl LED3_ON
	bl delay_1s
	bl LED3_OFF
	bl delay_1s
	bl loop


 LED1_ON:
	@通过GPIOx_ODR寄存器设置PE10引脚输出高电平
	ldr r0,=0x50006014
	ldr r1,[r0]
	orr r1,r1,#(0x1 << 10)
	str r1,[r0]
	mov pc,lr

 LED1_OFF:
    @通过GPIOx_ODR寄存器设置PE10引脚输出低电平
	ldr r0,=0x50006014
	ldr r1,[r0]
	and r1,r1,#(0x0 << 10)
	str r1,[r0]
	mov pc,lr

 LED2_ON:
	@通过GPIOx_ODR寄存器设置PF10引脚输出高电平
	ldr r0,=0x50007014
	ldr r1,[r0]
	orr r1,r1,#(0x1 << 10)
	str r1,[r0]
	mov pc,lr

 LED2_OFF:
    @通过GPIOx_ODR寄存器设置PF10引脚输出低电平
	ldr r0,=0x50007014
	ldr r1,[r0]
	and r1,r1,#(0x0 << 10)
	str r1,[r0]
	mov pc,lr

 LED3_ON:
	@通过GPIOx_ODR寄存器设置PE8引脚输出高电平
	ldr r0,=0x50006014
	ldr r1,[r0]
	orr r1,r1,#(0x1 << 8)
	str r1,[r0]
	mov pc,lr

 LED3_OFF:
    @通过GPIOx_ODR寄存器设置PE8引脚输出低电平
	ldr r0,=0x50006014
	ldr r1,[r0]
	and r1,r1,#(0x0 << 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