stm32汇编点亮nucleo的PA5口的led灯

;LED0 EQU 0x42218194 ;LED0 (PB5)的bit-bond地址
LED0 EQU 0x42210194
RCC_APB2ENR EQU 0x40021018
GPIOB_CRL EQU 0x40010800

Stack_Size EQU 0x00000400

AREA STACK, NOINIT, READWRITE, ALIGN=3
Stack_Mem SPACE Stack_Size
__initial_sp

AREA RESET, DATA, READONLY

__Vectors DCD __initial_sp ; Top of Stack
DCD Reset_Handler ; Reset Handler


AREA |.text|, CODE, READONLY

THUMB
REQUIRE8
PRESERVE8

ENTRY
Reset_Handler
BL LED_Init
MainLoop BL LED_ON
BL Delay
BL LED_OFF
BL Delay

B MainLoop

LED_Init
PUSH {R0,R1, LR}

LDR R0,=RCC_APB2ENR
ORR R0,R0,#0x04 ;使能GPIOA
LDR R1,=RCC_APB2ENR
STR R0,[R1]

LDR R0,=GPIOB_CRL
BIC R0,R0,#0XFF0FFFFF ;配置为模拟输入
LDR R1,=GPIOB_CRL
STR R0,[R1]

LDR R0,=GPIOB_CRL
ORR R0,R0,#0X00300000 ;推挽输出
LDR R1,=GPIOB_CRL
STR R0,[R1]

MOV R0,#1
LDR R1,=LED0
STR R0,[R1]

POP {R0,R1,PC}

LED_ON
PUSH {R0,R1, LR}

MOV R0,#0
LDR R1,=LED0
STR R0,[R1]

POP {R0,R1,PC}

LED_OFF
PUSH {R0,R1, LR}

MOV R0,#1
LDR R1,=LED0
STR R0,[R1]

POP {R0,R1,PC}

Delay
PUSH {R0,R1, LR}

MOVS R0,#0
MOVS R1,#0
MOVS R2,#0

DelayLoop0
ADDS R0,R0,#1

CMP R0,#330
BCC DelayLoop0

MOVS R0,#0
ADDS R1,R1,#1
CMP R1,#330
BCC DelayLoop0

MOVS R0,#0
MOVS R1,#0
ADDS R2,R2,#1
CMP R2,#15
BCC DelayLoop0

POP {R0,R1,PC}

END