嵌入式用汇编语言实现STM32的LED和USART

慧心的眼眸 · 发表于 2018-1-18 13:37:40

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            AREA RESET, DATA, READONLY

            DCD 0x20000000 + 1024 ;0
            DCD UserMain ;1
            DCD 0 ;NMI 2
            DCD 0 ;HardFault 3
            DCD 0 ;MemManage 4
            DCD 0 ; 5
            DCD 0 ; 6
            DCD 0 ; 7
            DCD 0 ; 8
            DCD 0 ; 9
            DCD 0 ; 10
            DCD 0 ; 11
            DCD 0 ; 12
            DCD 0 ; 13
            DCD 0 ; 14
            DCD SysTick_Handler ; 15
HelloString    DCB "Hello Word\n"
HelloEnd
HexTable       DCB "0123456789ABCDEF"
HexTableEnd

GPIOF_BASE    EQU    0x40021400
GPIOF_MODER    EQU    GPIOF_BASE + 0x00
GPIOF_OTYPER EQU    GPIOF_BASE + 0x04
GPIOF_OSPEEDR EQU    GPIOF_BASE + 0x08
GPIOF_PUPDR    EQU    GPIOF_BASE + 0x0C
GPIOF_IDR    EQU    GPIOF_BASE + 0x10
GPIOF_ODR    EQU    GPIOF_BASE + 0x14
GPIOF_BSRR    EQU    GPIOF_BASE + 0x18
GPIOF_AFRL    EQU    GPIOF_BASE + 0x20
GPIOF_AFRH    EQU    GPIOF_BASE + 0x24

GPIOA_BASE    EQU    0x40020000
GPIOA_MODER    EQU    GPIOA_BASE + 0x00
GPIOA_OTYPER EQU    GPIOA_BASE + 0x04
GPIOA_OSPEEDR EQU    GPIOA_BASE + 0x08
GPIOA_PUPDR    EQU    GPIOA_BASE + 0x0C
GPIOA_IDR    EQU    GPIOA_BASE + 0x10
GPIOA_ODR    EQU    GPIOA_BASE + 0x14
GPIOA_BSRR    EQU    GPIOA_BASE + 0x18
GPIOA_AFRL    EQU    GPIOA_BASE + 0x20
GPIOA_AFRH    EQU    GPIOA_BASE + 0x24

USART1_BASE    EQU    0x40011000
USART1_SR    EQU    USART1_BASE + 0x00
USART1_DR    EQU    USART1_BASE + 0x04
USART1_BRR    EQU    USART1_BASE + 0x08
USART1_CR1    EQU    USART1_BASE + 0x0C
USART1_CR2    EQU    USART1_BASE + 0x10
USART1_CR3    EQU    USART1_BASE + 0x14
USART1_GTPR    EQU    USART1_BASE + 0x18



RCC_BASE       EQU    0x40023800
RCC_CR       EQU    RCC_BASE + 0x00
RCC_PLLCFGR    EQU    RCC_BASE + 0x04
RCC_CFGR       EQU    RCC_BASE + 0x08
RCC_CIR       EQU    RCC_BASE + 0x0C
RCC_AHB1RSTR EQU    RCC_BASE + 0x10
RCC_AHB2RSTR EQU    RCC_BASE + 0x14
RCC_AHB3RSTR EQU    RCC_BASE + 0x18
RCC_APB1RSTR EQU    RCC_BASE + 0x20
RCC_APB2RRST EQU    RCC_BASE + 0x24
RCC_AHB1ENR    EQU    RCC_BASE + 0x30
RCC_AHB2ENR    EQU    RCC_BASE + 0x34
RCC_AHB3ENR    EQU    RCC_BASE + 0x38
RCC_APB1ENR    EQU    RCC_BASE + 0x40
RCC_APB2ENR    EQU    RCC_BASE + 0x44

SYSTICK_CTRL EQU    0xE000E010
SYSTICK_LOAD EQU    0xE000E014
SYSTICK_VAL    EQU    0xE000E018



            THUMB
            PRESERVE8
            AREA _UserMain, CODE, READONLY

            ENTRY
UserMain       PROC
            EXPORT UserMain

            LDR R0, =LedConfig
            BLX R0

            LDR R0, =SysTickConfig
            BLX R0

            MOV R10, #200

            LDR R0, =UartConfig
            BLX R0

SendString
            LDR R0, =HelloString
            LDR R1, =HelloEnd - HelloString
            BL UartSendString
            MOV R0, #0xAB
            BL UartSendHex
            B SendString

            ENDP


UartSendHex    ; R0
            PUSH {R1 - R3,LR}

            LDR R3, =HexTable
            MOV R4, R0
            LDR R2, =28
HexLoop
            LSR R1, R4, R2
            AND R1, #0x0F
            LDR R0, [R3, R1]
            PUSH {R1-R2}

            BL UartSendByte
            POP {R1-R2}
            CMP R2, #0
            BEQ HexExit
            SUB R2, #4
            B HexLoop

HexExit
            POP {R1-R3, PC}

UartConfig
            PUSH {LR}

            LDR R0, =RCC_AHB1ENR
            LDR R1, [R0]
            ORR R1, #0x01
            STR R1, [R0]

            LDR R0, =RCC_APB2ENR
            LDR R1, [R0]
            ORR R1, #0x10
            STR R1, [R0]

            LDR R0, =GPIOA_MODER
            LDR R1, [R0]
            BIC R1, #0x3C0000
            ORR R1, #0x280000
            STR R1, [R0]

            LDR R0, =GPIOA_OTYPER
            LDR R1, [R0]
            BIC R1, #0x600
            STR R1, [R0]

            LDR R0, =GPIOA_OSPEEDR
            LDR R1, [R0]
            ORR R1, #0x3C0000
            STR R1, [R0]

            LDR R0, =GPIOA_PUPDR
            LDR R1, [R0]
            BIC R1, #0x3C0000
            ORR R1, #0x140000
            STR R1, [R0]

            LDR R0, =GPIOA_AFRH
            LDR R1, [R0]
            BIC R1, #0xFF0
            ORR R1, #0x770
            STR R1, [R0]

            LDR R0, =USART1_CR1
            LDR R1, [R0]
            MOV R1, #0
            ORR R1, #0x08
            STR R1, [R0]

            LDR R0, =USART1_CR2
            MOV R1, #0
            STR R1, [R0]

            LDR R0, =USART1_CR3
            MOV R1, #0
            STR R1, [R0]

            LDR R0, =USART1_BRR
            LDR R1, =0x682
            STR R1, [R0]

            LDR R0, =USART1_CR1
            LDR R1, [R0]
            ORR R1, #0x2000
            STR R1, [R0]

            POP {PC}


UartSendByte ; R0
            PUSH {LR}
SendWait
            LDR R2, =USART1_SR
            LDR R1, [R2]
            TST R1, #0x80
            BEQ SendWait
            LDR R2, =USART1_DR
            STR R0, [R2]

            POP {PC}


UartSendString  ; R0 R1

            PUSH {LR}

            MOV R2, R0
StringLoop
            CMP R1, #0
            BEQ SendExit
            LDRB R0, [R2]
            PUSH {R1, R2}
            BL UartSendByte
            POP {R1, R2}
            SUB R1, #1
            ADD R2, #1
            B StringLoop

SendExit
            POP {PC}


SysTickConfig
            PUSH {LR}

            LDR R0, =SYSTICK_LOAD
            LDR R1, =1999
            STR R1, [R0]

            LDR R0, =SYSTICK_VAL
            LDR R1, =0
            STR R1, [R0]

            LDR R0, =SYSTICK_CTRL
            LDR R1, [R0]
            BIC R1, #0x04
            ORR R1, #0x03
            STR R1, [R0]

            POP {PC}


LedConfig
            PUSH {LR}

            LDR R0, =RCC_AHB1ENR
            LDR R1, [R0]
            ORR R1, #0x20
            STR R1, [R0]

            LDR R0, =GPIOF_MODER
            LDR R1, [R0]
            BIC R1, #0x3C0000
            ORR R1, #0x140000
            STR R1, [R0]

            LDR R0, =GPIOF_OTYPER
            LDR R1, [R0]
            BIC R1, #0x600
            STR R1, [R0]

            LDR R0, =GPIOF_OSPEEDR
            LDR R1, [R0]
            ORR R1, #0x3C0000
            STR R1, [R0]

            LDR R0, =GPIOF_PUPDR
            LDR R1, [R0]
            BIC R1, #0x3C0000
            ORR R1, #0x140000
            STR R1, [R0]

            LDR R0, =GPIOF_BSRR
            LDR R1, [R0]
            ORR R1, #0x600
            STR R1, [R0]

            POP{PC}



SysTick_Handler PROC
            EXPORT SysTick_Handler

            PUSH {LR}

            CMP R10, #0
            BNE Exit
            LDR R0, =GPIOF_ODR
            LDR R1, [R0]
            EOR R1, #0x600
            STR R1, [R0]
            MOV R10, #200

            POP {PC}

Exit
            SUB R10, #1

            POP{PC}

            ENDP

            END
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