arm_uart4实验

#include "uart4.h"                       
                                         
//UART                                   
                                         
//初始化                                 
void hal_uart4_init()                    
{                                        
    //rcc_init                           
        //使能GPIOB组控制器[1]=1         
        RCC->MP_AHB4ENSETR |= (0x1 << 1);
        //使能GPIOG组控制器[6]=1         
        RCC->MP_AHB4ENSETR |= (0x1 << 6);
        //使能uart组控制器[16]=1  
        RCC->MP_AHB4ENSETR |=(0x1 << 16);       
    //gpio_init  
        GPIOB->MODER &= (~(0x2 << 5));
        GPIOB->MODER |= (0x1 << 5);
        GPIOG->MODER &= (~(0x2 << 23));
        GPIOG->MODER |= (0x1 << 23);
        GPIOB->AFRL &= (~(0x8 << 11));
        GPIOB->AFRL |= (0x1 << 11);
        GPIOB->AFRH &= (~(0x6 << 15));
        GPIOB->AFRH |= (0x6 << 14);
    //uart_init
        USART4->CR1 &=(~(0x1 << 28));
        USART4->CR1 &=(~(0x1 << 12));
        USART4->CR1 &=(~(0x1 << 15));
        USART4->CR1 &=(~(0x1 << 10));
        USART4->CR1 |=(0x1 << 3);
        USART4->CR1 |=(0x1 << 2) ;
        USART4->CR1 |= 0x1;
        USART4->CR1 &=(~(0x1 << 13));
        USART4->CR1 &=(~(0x1 << 12));
        USART4->PRESC &= ~(0x7);  
        USART4->BRR=0x22b;                    
}                                        
//发送一个字符                           
void hal_put_char(const char str)        
{                                        
     
    while (!(USART4->ISR &(1<<7)));
    USART4->TDR=str;
    if(str=='\n'){
        hal_put_char('\r');
    }
                                    
}                                        
//接受一个字符                           
char hal_get_char()                      
{                                        
      
    char data;
    while(!(USART4->ISR &(1<<5)));
    data=(char)USART4->RDR;
    return data;
                                   
}                                        
// //发送一个字符串                         

// void hal_put_string(const char* string)  
// {                                        
     
//     while(*string !='\0'){
//         hal_put_string(*string);
//         string++;
//     }
                                    
// }                                        
// //接一个字符串                         
// char* hal_get_string()                   
// {                                        
//     int i=0;
//     char buff[128];
//     for(;i<49;i++){
//         buff[i]=hal_recvchar();
//         hal_put_string(buff[i]);
//         if (buff[i] == '\r')//代表串口调试助手的enter，串口调试助手没有\0
//         {
//             break;
//         }
//     }
//     buff[i]='\0';
//     hal_put_string('\n');
//     return buff;
                                   
// }

#include "uart4.h"

int main()
{
    hal_uart4_init();
    //hal_put_string("uart4 test");
    while(1)
    {
        hal_put_char(hal_get_char()+1);
        //hal_put_string(hal_get_string());
    }
}

#ifndef __UART_H__
#define __UART_H__
#include "stm32mp1xx_gpio.h"
#include "stm32mp1xx_rcc.h"
#include "stm32mp1xx_uart.h"
void hal_uart4_init();

void hal_put_char(const char str);

char hal_get_char();

void hal_put_string(const char* string);
char* hal_get_string();
#endif