rs232.c

IAR for ARM LPC2148的UART实验

//rs232.c
#include "rs232.h"

/**** UART0 ****/
void UART0Initialize(unsigned int baud) {
  unsigned int divisor = GetPclk() / (16 * baud);
  // 设置行控制寄存器
  U0LCR_bit.WLS   = 0x3;    // 8位数据
  U0LCR_bit.SBS   = 0x0;    // 1位停止位
  U0LCR_bit.PE    = 0x0;    // 无校验
  U0LCR_bit.DLAB  = 0x1;    // 允许DLAB
  // 除法因子
  U0DLL = divisor & 0xFF;
  U0DLM = (divisor >> 8) & 0xFF;
  U0LCR &= ~0x80;
  //配置引脚功能:  port0.0 -> TX0,  port0.1 -> RXD0
  PINSEL0_bit.P0_0 = 0x1;
  PINSEL0_bit.P0_1 = 0x1;
}

void UART0WriteChar(unsigned char ch0) {
  //当 U0LSR_bit.THRE = 0 时， U0THR 包含有效数据
  while (U0LSR_bit.THRE == 0);
  U0THR = ch0;
}

unsigned char UART0ReadChar(void) {
  //当 U0LSR_bit.DR = 1 时， U0RBR 包含有效数据
  while (U0LSR_bit.DR == 0);
  return U0RBR;
}

unsigned char UART0ReadChar_nostop(void) {
  //当 U0LSR_bit.DR = 1 时， U0RBR 包含有效数据
  if(U0LSR_bit.DR == 1) return U0RBR;
  else return 0;
}

void UART0WriteChar_nostop(unsigned char ch0) {
  //当 U0LSR_bit.THRE = 0 时， U0THR 包含有效数据
  if(U0LSR_bit.THRE == 1) U0THR = ch0;
}

/**** UART1 ****/
void UART1Initialize(unsigned int baud) {
  unsigned int divisor = GetPclk() / (16 * baud);
  // 设置行控制寄存器
  U1LCR_bit.WLS   = 0x3;    // 8位数据
  U1LCR_bit.SBS   = 0x0;    // 1位停止位
  U1LCR_bit.PE    = 0x0;    // 无校验
  U1LCR_bit.DLAB  = 0x1;    // 允许DLAB

  // 除法因子
  U1DLL = divisor & 0xFF;
  U1DLM = (divisor >> 8) & 0xFF;
  U1LCR &= ~0x80;

   //配置引脚功能:  port0.8 -> TX1,  port0.9 -> RXD1
  PINSEL0_bit.P0_8 = 0x1;
  PINSEL0_bit.P0_9 = 0x1;
}

void UART1WriteChar(unsigned char ch0) {
  //当 U1LSR_bit.THRE = 0 时， U1THR 包含有效数据
  while (U1LSR_bit.THRE == 0);
  U1THR = ch0;
}

unsigned char UART1ReadChar(void) {
  //当 U1LSR_bit.THRE = 0 时， U1RBR 包含有效数据
  while (U1LSR_bit.DR == 0);
  return U1RBR;
}


unsigned char UART1ReadChar_nostop(void) {
  //当 U1LSR_bit.DR = 1 时， U1RBR 包含有效数据
  if(U1LSR_bit.DR == 1) return U1RBR;
  else return 0;
}

void UART1WriteChar_nostop(unsigned char ch0) {
  //当 U1LSR_bit.THRE = 0 时， U1THR 包含有效数据
  if(U1LSR_bit.THRE == 1) U1THR = ch0;
}