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RCC寄存器地址映像

RCC_BASE EQU 0x40021000

RCC_CR EQU (RCC_BASE + 0x00)RCC_CFGR EQU (RCC_BASE + 0x04)RCC_CIR EQU (RCC_BASE + 0x08)RCC_APB2RSTR EQU (RCC_BASE + 0x0C)RCC_APB1RSTR EQU (RCC_BASE + 0x10)RCC_AHBENR EQU (RCC_BASE + 0x14)RCC_APB2ENR EQU (RCC_BASE + 0x18)RCC_APB1ENR EQU (RCC_BASE + 0x1C)RCC_BDCR EQU (RCC_BASE + 0x20)RCC_CSR EQU (RCC_BASE + 0x24)

AFIO寄存器地址映像

AFIO_BASE EQU 0x40010000

AFIO_EVCR EQU (AFIO_BASE + 0x00)AFIO_MAPR EQU (AFIO_BASE + 0x04)AFIO_EXTICR1 EQU (AFIO_BASE + 0x08)AFIO_EXTICR2 EQU (AFIO_BASE + 0x0C)AFIO_EXTICR3 EQU (AFIO_BASE + 0x10)AFIO_EXTICR4 EQU (AFIO_BASE + 0x14)

GPIOA寄存器地址映像

GPIOA_BASE EQU 0x40010800

GPIOA_CRL EQU (GPIOA_BASE + 0x00)GPIOA_CRH EQU (GPIOA_BASE + 0x04)GPIOA_IDR EQU (GPIOA_BASE + 0x08)GPIOA_ODR EQU (GPIOA_BASE + 0x0C)GPIOA_BSRR EQU (GPIOA_BASE + 0x10)GPIOA_BRR EQU (GPIOA_BASE + 0x14)GPIOA_LCKR EQU (GPIOA_BASE + 0x18)

GPIO C口控制

GPIOC_BASE EQU 0x40011000

GPIOC_CRL EQU (GPIOC_BASE + 0x00)GPIOC_CRH EQU (GPIOC_BASE + 0x04)GPIOC_IDR EQU (GPIOC_BASE + 0x08)GPIOC_ODR EQU (GPIOC_BASE + 0x0C)GPIOC_BSRR EQU (GPIOC_BASE + 0x10)GPIOC_BRR EQU (GPIOC_BASE + 0x14)GPIOC_LCKR EQU (GPIOC_BASE + 0x18)

串口1控制

USART1_BASE EQU 0x40013800

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)

NVIC寄存器地址

NVIC_BASE EQU 0xE000E000

NVIC_SETEN EQU (NVIC_BASE + 0x0010)NVIC_IRQPRI EQU (NVIC_BASE + 0x0400)NVIC_VECTTBL EQU (NVIC_BASE + 0x0D08)NVIC_AIRCR EQU (NVIC_BASE + 0x0D0C)SETENA0 EQU 0xE000E100SETENA1 EQU 0xE000E104

SysTick寄存器地址

SysTick_BASE EQU 0xE000E010

SYSTICKCSR EQU (SysTick_BASE + 0x00)SYSTICKRVR EQU (SysTick_BASE + 0x04)

FLASH缓冲寄存器地址

FLASH_ACR EQU 0x40022000

SCB_BASE

SCB_BASE EQU (SCS_BASE + 0x0D00)

常数定义

Bit0 EQU 0x00000001

Bit1 EQU 0x00000002Bit2 EQU 0x00000004Bit3 EQU 0x00000008Bit4 EQU 0x00000010Bit5 EQU 0x00000020Bit6 EQU 0x00000040Bit7 EQU 0x00000080Bit8 EQU 0x00000100Bit9 EQU 0x00000200Bit10 EQU 0x00000400Bit11 EQU 0x00000800Bit12 EQU 0x00001000Bit13 EQU 0x00002000Bit14 EQU 0x00004000Bit15 EQU 0x00008000Bit16 EQU 0x00010000Bit17 EQU 0x00020000Bit18 EQU 0x00040000Bit19 EQU 0x00080000Bit20 EQU 0x00100000Bit21 EQU 0x00200000Bit22 EQU 0x00400000Bit23 EQU 0x00800000Bit24 EQU 0x01000000Bit25 EQU 0x02000000Bit26 EQU 0x04000000Bit27 EQU 0x08000000Bit28 EQU 0x10000000Bit29 EQU 0x20000000Bit30 EQU 0x40000000Bit31 EQU 0x80000000

向量表

CDT MSP_TOP, DATA, READONLY

CDT Start, DATA, READONLYCDT NMI_Handler, DATA, READONLYCDT HardFault_Handler, DATA, READONLYCDT 0, DATA, READONLYCDT 0, DATA, READONLYCDT 0, DATA, READONLYCDT 0, DATA, READONLYCDT 0, DATA, READONLYCDT 0, DATA, READONLYCDT SysTick_Handler, DATA, READONLY

代码段

AREA .text, CODE, READONLY

ENTRY

Start

时钟系统设置

ldr r0, =RCC_CR

ldr r1, [r0]or r1, #Bit16str r1, [r0]

启动外部晶振

ldr r0, =RCC_CR

ldr r1, [r0]ands r1, #Bit17beq ClkOk

FLASH缓冲器

ldr r0, =FLASH_ACR

mov r1, #0x00000032str r1, [r0]

设置PLL锁相环倍率为7,HSE输入不分频

ldr r0, =RCC_CFGR

ldr r1, [r0]or r1, #(Bit18 :OR: Bit19 :OR: Bit20 :OR: Bit16 :OR: Bit14)or r1, #Bit10str r1, [r0]

启动PLL锁相环

ldr r0, =RCC_CR

ldr r1, [r0]or r1, #Bit24str r1, [r0]

选择PLL时钟作为系统时钟

ldr r0, =RCC_CFGR

ldr r1, [r0]or r1, #(Bit18 :OR: Bit19 :OR: Bit20 :OR: Bit16 :OR: Bit14)or r1, #Bit10or r1, #Bit1str r1, [r0]

其他RCC相关设置

ldr r0, =RCC_APB2ENR

mov r1, #(Bit14 :OR: Bit4 :OR: Bit2)str r1, [r0]

IO端口设置

ldr r0, =GPIOC_CRL

ldr r1, [r0]or r1, #(Bit28 :OR: Bit29)str r1, [r0]

PA.9串口0发射脚

ldr r0, =GPIOA_CRH

ldr r1, [r0]or r1, #(Bit4 :OR: Bit5)str r1, [r0]

AFIO 参数设置

ldr r0, =AFIO_MAPR

Systick 参数设置

ldr r0, =SYSTICKRVR

mov r1, #9000str r1, [r0]ldr r0, =SYSTICKCSRmov r1, #0x03str r1, [r0]

NVIC

ldr r0, =SETENA0

mov r1, #0x00800000str r1, [r0]ldr r0, =SETENA1mov r1, #0x00000100str r1, [r0]

切换成用户级线程序模式

ldr r0, =PSP_TOP

msr psp, r0mov r0, #3msr control, r0

初始化SRAM寄存器

mov r1, #0

ldr r0, =Flag1str r1, [r0]

初始化线程堆栈

ldr r0, =PSP_TOP

msr psp, r0mov r0, #3msr control, r0

主循环

main

ldr r0, =Flag1ldr r1, [r0]tst r1, #Bit1beq main

子程序 串口1发送一个字符

send_a_char

push {r0 - r3}ldr r2, =USART1_DRstr r0, [r2]

子程序 led闪烁

LedFlas

push {r0 - r3}ldr r0, =Flag1ldr r1, [r0]tst r1, #Bit0beq ONLED

ONLED

ldr r0, =b_flas

mov r1, #0str r1, [r0]

LedEx

ldr r0, =GPIOC_BRR

ldr r1, [r0]or r1, #Bit7str r1, [r0]

异常程序

NMI_Handler

bx lr

HardFault_Handler

bx lr

SysTick_Handler

ldr r0, =SysTimldr r1, [r0]add r1, #1str r1, [r0]cmp r1, #500bcc TickExitmov r1, #0str r1, [r0]ldr r0, =b_05smov r1, #1str r1, [r0]

TickExit

bx lr

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