- /************************************************
- 程序实现3 printf实现
- **************************************************/
- #include "sys.h"
- #include "delay.h"
- #include "stdio.h"
- void RCC_Configuration(void);
- void GPIO_Configuration(void);
- void USART_Configuration(u32 Baudrate);
- int fputc(int ch, FILE *f)//重定向,让printf输出到串口
- {
- USART_SendData(USART1,ch);
- while (USART_GetFlagStatus(USART1, USART_FLAG_TC) == RESET);
- return ch;
- }
- int main(void)
- {
- u8 i,data;
- RCC_Configuration();
- GPIO_Configuration();
- USART_Configuration(9600);
- data = 'A';
- for(i=0;i<30;i++)
- {
- USART_SendData(USART1, data);
- data++;
- while(USART_GetFlagStatus(USART1,USART_FLAG_TC)==RESET);
- }
- printf("yuanbao");
- }
- void RCC_Configuration(void)
- {
- /*---------------使用外部RC晶振----------*/
- RCC_DeInit(); //设置时钟为缺省值
- RCC_HSEConfig(RCC_HSE_ON); //使能外部高速晶振
- while(RCC_GetFlagStatus(RCC_FLAG_HSERDY) == RESET);//等待HSE准备就绪
- FLASH_PrefetchBufferCmd(FLASH_PrefetchBuffer_Enable); //使能指令预取
- FLASH_SetLatency(FLASH_Latency_2); //等待2个周期
- RCC_HCLKConfig(RCC_SYSCLK_Div1); //HCLK = SYSCLK
- RCC_PCLK2Config(RCC_HCLK_Div1); //PCLK2 = HCLK
- RCC_PCLK1Config(RCC_HCLK_Div2); //PCLK1 = HCLK/2
- RCC_PLLConfig(RCC_PLLSource_HSE_Div1,RCC_PLLMul_9); //PLLCLK = 72MHZ
- RCC_PLLCmd(ENABLE); //Enable PLLCLK
- while(RCC_GetFlagStatus(RCC_FLAG_PLLRDY) == RESET); //Wait PLL is ready
- RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK); //SYSCLK = PLLCLK
- while(RCC_GetSYSCLKSource()!= 0x08); //Wait PLLCLK as system clock
- //---------打开相应外设时钟--------------------
- RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE); //使能APB2外设的GPIOA的时钟
- RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC,ENABLE);
- RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1,ENABLE);
- RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE);
- }
- void GPIO_Configuration(void)
- {
- GPIO_InitTypeDef GPIO_InitStructure; //声明一个结构体变量
- GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9; //
- GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; //管脚频率为50MHZ
- GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
- GPIO_Init(GPIOA,&GPIO_InitStructure); //初始化GPIOA寄存器
- GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10; //选择
- GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
- GPIO_Init(GPIOA,&GPIO_InitStructure); //初始化GPIOA寄存器
- }
- void USART_Configuration(u32 Baudrate)
- {
- USART_InitTypeDef USART_InitStructure;
- USART_InitStructure.USART_BaudRate = Baudrate;
- USART_InitStructure.USART_WordLength = USART_WordLength_8b;
- USART_InitStructure.USART_StopBits = USART_StopBits_1;
- USART_InitStructure.USART_Parity = USART_Parity_No;
- USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
- USART_InitStructure.USART_Mode = USART_Mode_Tx | USART_Mode_Rx;
- USART_Init(USART1, &USART_InitStructure);
- USART_Cmd(USART1,ENABLE);
- }
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