电子系统设计课程笔记

// 宏定义，定义了各个寄存器的地址和偏移量
#define GPIOA_CRL   (*(volatile unsigned*)(0X40010800+0x000)) 
#define GPIOA_CRH   (*(volatile unsigned*)(0X40010800+0x004))
#define GPIOA_ODR   (*(volatile unsigned*)(0X40010800+0x00C)) 
#define GPIOB_CRL   (*(volatile unsigned*)(0x40010C00+0x000)) 
#define GPIOB_CRH   (*(volatile unsigned*)(0x40010C00+0x004)) 
#define GPIOB_ODR   (*(volatile unsigned*)(0x40010C00+0x00C)) 
#define RCC_APB2ENR (*(volatile unsigned*)(0x40021000+0x018)) 

// 延时函数，i为延时的时钟周期数
void delay(unsigned int i){
	while(i--);
}

int main(void){
	// 使能GPIOB和GPIOA时钟
	RCC_APB2ENR|=1<<3;
	RCC_APB2ENR|=1<<2;

	// 初始化GPIOA和GPIOB的控制寄存器
	GPIOA_CRL&=~(0xFFFFFFFF);
	GPIOA_CRH&=~(0xFFFFFFFF);
	GPIOA_CRL|=0x33333333;
	GPIOA_CRH|=0x33333333;

	GPIOB_CRL&=~(0xFFFFFFFF);
	GPIOB_CRH&=~(0xFFFFFFFF);
	GPIOB_CRL|=0x33333333;
	GPIOB_CRH|=0x33333333;

	int i = 0;

	while(1){
		// 用循环控制16个LED在GPIOA和GPIOB之间闪烁
		for(i = 0;i<16;i++){
			delay(50000);
			GPIOA_ODR^=1<<i;
		}
		for(i = 0;i<16;i++){
			delay(50000);
			GPIOB_ODR^=1<<i;
		}
	}
}

#define GPIOB_CRL (*(volatile unsigned int*)(0x40010C00+0x00))
#define GPIOB_IDR (*(volatile unsigned int*)(0x40010C00+0x08))
#define GPIOC_CRL (*(volatile unsigned int*)(0x40011000+0x00))
#define GPIOC_CRH (*(volatile unsigned int*)(0x40011000+0x04))
#define GPIOC_ODR (*(volatile unsigned int*)(0x40011000+0x0C))
#define RCC_APB2ENR (*(volatile unsigned int*)(0x40021000+0x18))


unsigned int num[10] = {0x3f, 0x06, 0x5b, 0x4f, 0x66, 0x6d, 0x7d, 0x07, 0x7f, 0x6f};
void delay(int iterations) {
    for (int i=0; i<iterations; i++) {
        asm("nop");
    }
}

int main(void){

    int value = 0;

    RCC_APB2ENR|=1<<3;
    RCC_APB2ENR|=1<<4;

    GPIOB_CRL &= ~0x0000000F;
    GPIOB_CRL |= 0x00000008;

    GPIOC_CRL &= ~(0xFFFF);
    GPIOC_CRH &= ~((0xF<<20)|(0xF<<16));
    GPIOC_CRL |= 0x33333333;

    while(1){
        if(!(GPIOB_IDR & 0x01)){ 
						delay(20);
						if(!(GPIOB_IDR & 0x01)){
							value++;
							while(!(GPIOB_IDR & 0x01));
						}
        }
        if(!(GPIOB_IDR & 0x02)){ 
						delay(20);
						if(!(GPIOB_IDR & 0x02)){
							value--;
							while(!(GPIOB_IDR & 0x02));
						}
        }
        if(value>9){
            value = 0;
        }
        if(value<0){
            value = 9;
        }
        GPIOC_ODR = (~num[value]) & 0x7F;
    }
}