TMS320F28027: 用开发板和例程SCI只能发送，无法接收串口助手的输入

1.用28027开发板直接用SCI例程以下语句的主函数烧写，开发环境CCS6.0，仅能实现启动后串口助手显示MCU发送的一段文字，自己输入后无法显示出来。

#include "DSP28x_Project.h"     // Device Headerfile and Examples Include File

// Prototype statements for functions found within this file.
void scia_echoback_init(void);
void scia_fifo_init(void);
void scia_xmit(int a);
void scia_msg(char *msg);

// Global counts used in this example
Uint16 LoopCount;
Uint16 ErrorCount;

void main(void)
{

    Uint16 ReceivedChar;
    char *msg;

// Step 1. Initialize System Control:
// PLL, WatchDog, enable Peripheral Clocks
// This example function is found in the DSP2802x_SysCtrl.c file.
   InitSysCtrl();

// Step 2. Initalize GPIO:
// This example function is found in the DSP2802x_Gpio.c file and
// illustrates how to set the GPIO to it's default state.
   // InitGpio(); Skipped for this example

// For this example, only init the pins for the SCI-A port.
// This function is found in the DSP2802x_Sci.c file.
   InitSciaGpio();

// Step 3. Clear all interrupts and initialize PIE vector table:
// Disable CPU interrupts
   DINT;

// Initialize PIE control registers to their default state.
// The default state is all PIE interrupts disabled and flags
// are cleared.
// This function is found in the DSP2802x_PieCtrl.c file.
   InitPieCtrl();

// Disable CPU interrupts and clear all CPU interrupt flags:
   IER = 0x0000;
   IFR = 0x0000;

// Initialize the PIE vector table with pointers to the shell Interrupt
// Service Routines (ISR).
// This will populate the entire table, even if the interrupt
// is not used in this example.  This is useful for debug purposes.
// The shell ISR routines are found in DSP2802x_DefaultIsr.c.
// This function is found in DSP2802x_PieVect.c.
   InitPieVectTable();

// Step 4. Initialize all the Device Peripherals:
// This function is found in DSP2802x_InitPeripherals.c
// InitPeripherals(); // Not required for this example

// Step 5. User specific code:

    LoopCount = 0;
    ErrorCount = 0;

    scia_fifo_init();      // Initialize the SCI FIFO
    scia_echoback_init();  // Initalize SCI for echoback

    msg = "\r\n\n\nHello World!\0";
    scia_msg(msg);

    msg = "\r\nYou will enter a character, and the DSP will echo it back! \n\0";
    scia_msg(msg);

    for(;;)
    {
       msg = "\r\nEnter a character: \0";
       scia_msg(msg);

       // Wait for inc character
       while(SciaRegs.SCIFFRX.bit.RXFFST !=1) { } // wait for XRDY =1 for empty state

       // Get character
       ReceivedChar = SciaRegs.SCIRXBUF.all;

       // Echo character back
       msg = "  You sent: \0";
       scia_msg(msg);
       scia_xmit(ReceivedChar);

       LoopCount++;
    }

}

// Test 1,SCIA  DLB, 8-bit word, baud rate 0x000F, default, 1 STOP bit, no parity
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;
    SciaRegs.SCICTL2.bit.RXBKINTENA =1;

    // SCI BRR = LSPCLK/(SCI BAUDx8) – 1
    #if (CPU_FRQ_60MHZ)
        SciaRegs.SCIHBAUD    =0x0000;  // 9600 baud @LSPCLK = 15MHz (60 MHz SYSCLK).
        SciaRegs.SCILBAUD    =0x00C2;
    #elif (CPU_FRQ_50MHZ)
        SciaRegs.SCHBAUD     =0x0000;  // 9600 baud @LSPCLK = 12.5 MHz (50 MHz SYSCLK)
    #elif (CPU_FRQ_40MHZ)    =0x00A1;
        SciaRegs.SCIHBAUD    =0x0000;  // 9600 baud @LSPCLK = 10MHz (40 MHz SYSCLK).
        SciaRegs.SCILBAUD    =0x0081;
    #endif
        SciaRegs.SCICCR.bit.LOOPBKENA=1;
    SciaRegs.SCICTL1.all =0x0023;  // Relinquish SCI from Reset
}

// Transmit a character from the SCI
void scia_xmit(int a)
{
    while (SciaRegs.SCIFFTX.bit.TXFFST != 0) {}
    SciaRegs.SCITXBUF=a;

}

void scia_msg(char * msg)
{
    int i;
    i = 0;
    while(msg[i] != '\0')
    {
        scia_xmit(msg[i]);

        i++;
    }
}

// Initalize the SCI FIFO
void scia_fifo_init()
{
    SciaRegs.SCIFFTX.all=0xE040;
    SciaRegs.SCIFFRX.all=0x2044;
    SciaRegs.SCIFFCT.all=0x0;

}

//===========================================================================
// No more.
//===========================================================================

Ben Qin：

你好，请用单步调试以及打断点的方式看看具体是哪一步指令出错。

,

user1986089：

  // Get character       ReceivedChar = SciaRegs.SCIRXBUF.all;

断点到这里就无法进入了，从串口助手输入也进入不了，用的controlcard开发板USB直连。

msg = "\r\n\n\nHello World!\0";    scia_msg(msg);

    msg = "\r\nYou will enter a character, and the DSP will echo it back! \n\0";这里都正常

,

user1986089：

SciaRegs.SCIFFTX.bit.TXFFST一直为0

,

Ben Qin：

你的C2000ware是什么版本的？请用最新版本的C2000ware试一下。