一、IO配置

　　以SCIA为例：使用的是GPIO35–SCITXDA    GPIOA36–SCIRXDA

　　使用寄存器：

　　GPBPUD ：设置上拉  GPIO32-GPIO63   对应位0 使能上拉

　　GPBQSEL1：

　　GPBMUX1：IO模式选择

　　代码如下：

    GpioCtrlRegs.GPBPUD.bit.GPIO36 = 0;    // Enable pull-up for GPIO28 (SCIRXDA)//使能内部上拉
    GpioCtrlRegs.GPBPUD.bit.GPIO35 = 0;       // Enable pull-up for GPIO29 (SCITXDA)//使能内部上拉
    GpioCtrlRegs.GPBQSEL1.bit.GPIO36 = 3;  // Asynch input GPIO28 (SCIRXDA) //设置为异步输入模式

    GpioCtrlRegs.GPBMUX1.bit.GPIO36 = 1;   // Configure GPIO28 for SCIRXDA operation  //配置为外设模式
    GpioCtrlRegs.GPBMUX1.bit.GPIO35 = 1;   // Configure GPIO29 for SCITXDA operation//配置为外设模式

 设置FIFO寄存器：

void scia_fifo_init()
{
    SciaRegs.SCIFFTX.all=0xE040;//使能FIFO;清除发送中断标志位；禁止FIFO发送中断；
                                //发送中断级别定义为0；
    SciaRegs.SCIFFRX.all=0x204f;//清除FIFO溢出标志位；清除溢出接受中断标志位；禁止
                                //FF接受中断；接受中断级别为16；
    SciaRegs.SCIFFCT.all=0x0;//SCITXBUF到移位寄存器传送不延迟

}

设置SCI相关寄存器:  寄存器描述见http://www.ti.com/lit/ug/sprufz5a/sprufz5a.pdf

void scia_echoback_init()
{
    // Note: Clocks were turned on to the SCIA peripheral
    // in the InitSysCtrl() function

     SciaRegs.SCICCR.all =0x0007;   // 1 stop bit,  No loopback
                                   // No parity,8 char bits,
                                   // async mode, idle-line protocol
    SciaRegs.SCICTL1.all =0x0003;  // enable TX, RX, internal SCICLK,
                                   // Disable RX ERR, SLEEP, TXWAKE
    SciaRegs.SCICTL2.all =0x0003;
    SciaRegs.SCICTL2.bit.TXINTENA =1;//开启接收中断
    SciaRegs.SCICTL2.bit.RXBKINTENA =1;//开启发送中断
    #if (CPU_FRQ_150MHZ)
          SciaRegs.SCIHBAUD    =0x0001;  // 9600 baud @LSPCLK = 37.5MHz.
          SciaRegs.SCILBAUD    =0x00E7;
    #endif
    #if (CPU_FRQ_100MHZ)
      SciaRegs.SCIHBAUD    =0x0001;  // 9600 baud @LSPCLK = 20MHz.
      SciaRegs.SCILBAUD    =0x0044;
    #endif
    SciaRegs.SCICTL1.all =0x0023;  // Relinquish SCI from Reset
}

波特率计算方式：

发生一个字节：

void scia_xmit(int a)
{
    while (SciaRegs.SCIFFTX.bit.TXFFST != 0) {}
    SciaRegs.SCITXBUF=a;

}

 使用SICA  发送，串口中断接收：

　　配置参数如下：

static void Init_SCI_A(Uint32 Baud)
{
    //Init  IO
    Uint16 BRR=0;
    EALLOW;
     GpioCtrlRegs.GPBPUD.bit.GPIO36 = 0;    // Enable pull-up for GPIO28 (SCIRXDA)
     GpioCtrlRegs.GPBPUD.bit.GPIO35 = 0;       // Enable pull-up for GPIO29 (SCITXDA)
     GpioCtrlRegs.GPBQSEL1.bit.GPIO36 = 3;  // Asynch input GPIO28 (SCIRXDA)
     GpioCtrlRegs.GPBMUX1.bit.GPIO36 = 1;   // Configure GPIO28 for SCIRXDA operation
     GpioCtrlRegs.GPBMUX1.bit.GPIO35 = 1;   // Configure GPIO29 for SCITXDA operation
    EDIS;

    //set RX  interrput function
    EALLOW;
    PieVectTable.SCIRXINTA = &SciaRxIsr;
    EDIS;

   //set SCIA register
   SciaRegs.SCICCR.all =0x0007;   // 1 stop bit,  No loopback
                                  // No parity,8 char bits,
                                  // async mode, idle-line protocol
   SciaRegs.SCICTL1.all =0x0003;  // enable TX, RX, internal SCICLK,
                                  // Disable RX ERR, SLEEP, TXWAKE
   SciaRegs.SCICTL2.bit.TXINTENA =0;//close TX interrput
   SciaRegs.SCICTL2.bit.RXBKINTENA =1;
    //set Baud BRR= LSPCLK/(Baud*8)-1
   BRR = SCI_LSPCLK/(Baud*8)-1;
   SciaRegs.SCIHBAUD    = (BRR>>8);  // 9600 baud @LSPCLK = 37.5MHz.
   SciaRegs.SCILBAUD    = (BRR&0x00ff);
//   SciaRegs.SCIHBAUD    =0x0001;  // 9600 baud @LSPCLK = 37.5MHz.
//   SciaRegs.SCILBAUD    =0x00E7;
   SciaRegs.SCICTL1.all =0x0023;     // Relinquish SCI from Reset

   EALLOW;
   //set SCI interrput Group
    PieCtrlRegs.PIECTRL.bit.ENPIE = 1;   // Enable the PIE block
    PieCtrlRegs.PIEIER9.bit.INTx1=1;     // PIE Group 9, int1  enable SCIA_RX
    //PieCtrlRegs.PIEIER9.bit.INTx2=1;     // PIE Group 9, INT2  enable SCIA_TX
   EDIS;
}

　　发送数据代码：

//send one byte data
static void scia_xmit(int a)
{
    while (SciaRegs.SCIFFTX.bit.TXFFST != 0) {}
    SciaRegs.SCITXBUF=a;
}

//send string
void scia_msg(char * msg)
{
    int i;
    i = 0;
    while(msg[i] != '')
    {
        scia_xmit(msg[i]);
        i++;
    }
}