(kinetis K60)UART寄存器 串口收發數據

串口初始化……

 

main.c 文件

#include "common.h"
#include "uart.h"
#include "isr.h"

void UART4_Init(U32);                     
void delay(long count);
void Uart4_SendByte(U8 Char);


void main (void)
{
  char str[]="hello cortex-m4  ";
  U8 i;
  
  DisableInterrupts;  
  UART4_Init(57600);
  EnableInterrupts;
  
  while(1)
  {
    for(i=0; str[i]!='\0'; i++)
      Uart4_SendByte(str[i]);
    delay(7000000);
  }
}

void delay(long count)
{
  while(count--)
      asm("nop");
}

void UART4_Init(U32 BaudRate)
{
  U16 ubd, brfa;

  U8 temp;
    
  PORTC_PCR15 = PORT_PCR_MUX(0x3);   //引腳使能
  PORTC_PCR14 = PORT_PCR_MUX(0x3); 
  SIM_SCGC1 |= SIM_SCGC1_UART4_MASK;   //時鍾使能


  UART4_C2 &= ~((1<<2) | (1<<3)); //禁止發送接收   控制寄存器C2
  
  UART4_C1 = 0;  //控制器C1 全部使用默認配備

  ubd = (U16)((50000000)/(BaudRate * 16));   //波特率設置

  UART4_BDH = (U8)ubd>>8;  
  UART4_BDL = (U8)(ubd);
  
  
  brfa = (((50000000)/(BaudRate * 16)) - (ubd * 32));  //波特率微調 1/32的增量

  temp = UART4_C4 & ~(UART_C4_BRFA(0x1F)); 
  UART4_C4 = temp | UART_C4_BRFA(brfa);
  

  UART4_C2 |= ((1<<2) | (1<<3));  //允許發送接收

  return;
}

void Uart4_SendByte(U8 Char)
{

    while(!(UART_S1_REG(UART4_BASE_PTR) & UART_S1_TDRE_MASK)); //UARTx_S1狀態寄存器
    UART4_D = Char;
    return;
}

串口接收函數

U8 Uart4_Receive(void)
{
    U8 Receivechar;
    while(!(UART_S1_REG(UART4_BASE_PTR) & UART_S1_RDRF_MASK));       //查詢是否接受到數據
    Receivechar  =   UART4_D;                    //接受到8位的數據
    return(Receivechar);
}