① 时钟系统：
时钟源 — >外部晶振
锁相环 ： 倍频 + 分频
AHB（关注AHB1），APB（关注APB1，APB2）
② 总线
AMBA : AHB( 高速总线 ) + APB（外设总线）
③ 时钟树
④ 任务：使用按键控制输入输出
PA0低电平 未按下 高电平 按下
//PA0硬件初始化
时钟源打开
配置PA0
输入
上拉/下拉
应用
输入数据寄存器采样（while下 轮训 此寄存器 ）
代码：
#include
#define Time_Delay 5000
#define RCC_ADDR 0x40023800
#define RCC_AHB1ENR *((unsigned int *)(RCC_ADDR+0x30))
#define GPIOA_ADDR 0x40020000
#define GPIOA_IDR *((unsigned int *)(GPIOA_ADDR + 0x10))
#define GPIOC_ADDR 0x40020800
#define GPIOC_IDR *((unsigned int *)(GPIOC_ADDR + 0x10))
#define GPIOH_ADDR 0x40021C00
#define GPIOH_MODER *((unsigned int *)(GPIOH_ADDR + 0x00))
#define GPIOH_OTYPER *((unsigned int *)(GPIOH_ADDR + 0x04))
#define GPIOH_OSPEEDER *((unsigned int *)(GPIOH_ADDR + 0x08))
#define GPIOH_PUPDR *((unsigned int *)(GPIOH_ADDR + 0x0C))
#define GPIOH_ODR *((unsigned int *)(GPIOH_ADDR + 0x14))
#define GPIOI_ADDR 0x40022000
#define GPIOI_MODER *((unsigned int *)(GPIOI_ADDR + 0x00))
#define GPIOI_OTYPER *((unsigned int *)(GPIOI_ADDR + 0x04))
#define GPIOI_OSPEEDER *((unsigned int *)(GPIOI_ADDR + 0x08))
#define GPIOI_PUPDR *((unsigned int *)(GPIOI_ADDR + 0x0C))
#define GPIOI_ODR *((unsigned int *)(GPIOI_ADDR + 0x14))
int k=0;
int i[7]={1,2,3,4,5,6,7};
void delay(unsigned int n)
{
unsigned int i,j;
for(i=0;i for(j=0;j<1000;j++); } void Beep() { GPIOI_MODER = 0x400000; GPIOI_OTYPER = 0x00; GPIOI_PUPDR = 0x400000; GPIOI_OSPEEDER = 0x00; GPIOI_ODR = 0x800; delay(Time_Delay); GPIOI_ODR = 0x00; } void Red() { GPIOH_MODER = 0x100000; //Êä³ö GPIOH_OTYPER = 0x00; //ÍÆÍì GPIOH_PUPDR = 0x100000; //ÉÏÀ GPIOH_OSPEEDER = 0x00; //µÍËÙ GPIOH_ODR = 0x00; //µÍ // Beep(); // GPIOH_ODR = 0x400; //¸ß // delay(Time_Delay); } void Yellow() { GPIOH_MODER = 0x500000; GPIOH_OTYPER = 0x00; GPIOH_PUPDR = 0x500000; GPIOH_OSPEEDER = 0x00; GPIOH_ODR = 0x00; // Beep(); // GPIOH_ODR = 0xC00; // delay(Time_Delay); } void Green() { GPIOH_MODER = 0x400000; GPIOH_OTYPER = 0x00; GPIOH_PUPDR = 0x400000; GPIOH_OSPEEDER = 0x00; GPIOH_ODR = 0x00; // Beep(); // GPIOH_ODR = 0x800; // delay(Time_Delay); } void Cyan() { GPIOH_MODER = 0x1400000; GPIOH_OTYPER = 0x00; GPIOH_PUPDR = 0x1400000; GPIOH_OSPEEDER = 0x00; GPIOH_ODR = 0x00; // Beep(); // GPIOH_ODR = 0x1800; // delay(Time_Delay); } void Blue() { GPIOH_MODER = 0x1000000; GPIOH_OTYPER = 0x00; GPIOH_PUPDR = 0x1000000; GPIOH_OSPEEDER = 0x00; GPIOH_ODR = 0x00; // Beep(); // GPIOH_ODR = 0x1000; // delay(Time_Delay); } void Purple() { GPIOH_MODER = 0x1100000; GPIOH_OTYPER = 0x00; GPIOH_PUPDR = 0x1100000; GPIOH_OSPEEDER = 0x00; GPIOH_ODR = 0x00; // Beep(); // GPIOH_ODR = 0x1400; // delay(Time_Delay); } void White() { GPIOH_MODER = 0x1500000; GPIOH_OTYPER = 0x00; GPIOH_PUPDR = 0x1500000; GPIOH_OSPEEDER = 0x00; GPIOH_ODR = 0x00; // Beep(); // GPIOH_ODR = 0x1C00; // delay(Time_Delay); } void Key_1() { if((GPIOA_IDR & 0x01) == 0x01) { while((GPIOA_IDR & 0x01) == 0x01) { switch(i[k]) { case 1:Red();Beep();break; case 2:Yellow();Beep();break; case 3:Green();Beep();break; case 4:Cyan();Beep();break; case 5:Blue();Beep();break; case 6:Purple();Beep();break; case 7:White();Beep(); } } k++; if(k == 7) k=0; } else { switch(i[k]) { case 2:GPIOH_ODR = 0x400;break; case 3:GPIOH_ODR = 0xC00;break; case 4:GPIOH_ODR = 0x800;break; case 5:GPIOH_ODR = 0x1800;break; case 6:GPIOH_ODR = 0x1000;break; case 7:GPIOH_ODR = 0x1400;break; case 1:GPIOH_ODR = 0x1C00; } } } void Key_2() { if((GPIOC_IDR & 0x2000) == 0x2000) { Red(); Beep(); Green(); Beep(); Blue(); Beep(); } } int main(void) { //ʹÄÜʱÖÓÔ´ RCC_AHB1ENR = 0x00100185; //A,C,H,I while(1) { Key_1(); } }