2021年08月24日 | LPC1788---串口设置

LPC1788学习之串口学习-寄存器操作

接收数据使用中断接收---发送暂时是直接发送--简单的寄存器操作-记下不忘记！

#include "uart_lpc1788.h"

uint32_t Receive_Sign; //接收数据下标--接收数据个数

uint8_t  Receive_Buf[UART_RING_BUFSIZE]; //接收数组

/*-----------------------串口0初始化------------------*/

void Uart0_Init(uint32_t clk, uint32_t baudrate)

{

    uint32_t tmp;

    uint16_t divisorInt;

    LPC_IOCON->P0_2=0X21;

    LPC_IOCON->P0_3=0X21;

    LPC_SC->PCONP |= (1<<3); //外设时钟使能

//--------------------------------------------- 

    LPC_UART0->FCR=0X07;

    LPC_UART0->FCR=0X00;

    while (LPC_UART0->LSR & 0X01)

    {

        tmp = LPC_UART0->RBR;  //假读取去清空

    }

    LPC_UART0->TER = 0x80;

    while (!(LPC_UART0->LSR & 0x20));

    LPC_UART0->TER = 0;

    LPC_UART0->IER = 0;

    LPC_UART0->LCR = 0;

    LPC_UART0->ACR = 0;

    LPC_UART0->RS485CTRL = 0;

    LPC_UART0->RS485DLY = 0;

    LPC_UART0->ADRMATCH = 0;

    tmp = LPC_UART0->LSR;  //获取线状态寄存器

//-------------------------------------

    divisorInt =Uart0GetDivisorByBaudrate(clk,baudrate);   

    LPC_UART0->LCR |= 0x80; //使能访问除数寄存器

    LPC_UART0->DLM = (divisorInt>>8) & 0xFF;

    LPC_UART0->DLL = divisorInt & 0xFF;

    LPC_UART0->LCR &= (~0x80) & 0xFF; //禁止访问

//------------------------------------------ 

    tmp = (LPC_UART0->LCR & (0x80 | 0x40)) & 0xFF;

    tmp |= 0x03;  //8位数据-1个停止位-禁止奇偶校验

    LPC_UART0->LCR = (uint8_t)(tmp & 0xFF);

//----------------------------------------------

    tmp=0;

    tmp |= 0x01; //使能FIFO

    tmp |= 0x00; //触发点0-一个字符触发中断

    tmp |= 0x04; //发送缓存

    tmp |= 0x02; //接收缓存

    LPC_UART0->FCR = tmp & 0xFF;

//------------------------------------------------

    LPC_UART0->TER |= 0x80;//发送使能

    LPC_UART0->IER|= 0x01& 0x307; //使能RD数据接收中断

    LPC_UART0->IER|= 0x04& 0x307;  //使能RX线状态中断

//----------------------------------------------------

    Receive_Sign=0; 

//--------------------------------------

    NVIC_SetPriority(UART0_IRQn, ((0x01<<3)|0x01));

    NVIC_EnableIRQ(UART0_IRQn);

}

/*-------------------串口0中断函数----------------------*/

void UART0_IRQHandler(void)

{

    uint32_t  tmp, tmp1;

    tmp = ((LPC_UART0->IIR) & 0x3CF) & (7<<1);   //获取中断标识

    if (tmp == (3<<1)) //线状态中断

    {

        tmp1 = ((LPC_UART0->LSR) & 0xFF);

        tmp1 &= ((1<<1) | (1<<2) | (1<<3)| (1<<4) | (1<<7));

        if (tmp1)  //有错误

        {

            while (1){}

        }

    }

    if ((tmp == (2<<1)) || (tmp == (6<<1)))//接收数据中断--超时中断

    {

        Receive_Buf[Receive_Sign]= (LPC_UART0->RBR & 0xFF);  //读取数据

        Receive_Sign++;

    }

    if (tmp == (1<<1))//THRE发送中断

    {

        //UART_IntTransmit(); //发送数据--未使用

    }

}

/*-----------发送指定数组----------------*/

void UART0_SendStr(uint8_t *txbuf)

{

    uint8_t *pChar = txbuf;

    while(*pChar!='')

    {

        while (!(LPC_UART0->LSR & (1<<5)));//发送保持寄存器为空

        LPC_UART0->THR = (*pChar) & 0xFF; //发送数据

        pChar++; 

    }

}

/*---------发送指定数组的指定长度-----不知道为啥-buflen不能使用sizeof函数----------*/

void UART0_SendStrNum(uint8_t *txbuf,uint32_t buflen)

{

    uint16_t i;

    uint8_t *pChar = txbuf;

    for(i=0;i    {

        while (!(LPC_UART0->LSR & (1<<5)));//发送保持寄存器为空

        LPC_UART0->THR = (*pChar) & 0xFF; //发送数据

        pChar++;

    }

}

/*----------根据外设频率与波特率计算分频寄存器的值----------*/

uint16_t Uart0GetDivisorByBaudrate(uint32_t clk, uint32_t baudrate)

{

    float divisor;

    uint16_t divisorInt;

    divisor = (float)clk/(baudrate*16);    

    divisorInt = (uint16_t)(divisor/256);    

    divisor-=(divisorInt*256);

    if ((divisor - (uint32_t)divisor) > 0.5F)  //四舍五入

    {

        divisorInt = (divisorInt << 8) | ((uint8_t)divisor + 1);

    }

    else

    {

        divisorInt = (divisorInt << 8) | (uint8_t)divisor;

    }    

    return divisorInt;  //高8位-DLM--低8位-DLL

}