28335串口编程问题求解！

只看该作者 · 2014-11-14 14:30

本帖最后由 scottly 于 2014-11-14 18:54 编辑

1.用网上买的开发板。上面用的是SCIC串口，接了MAX232电平转换芯片；和PC电脑串口通信正常，串口助手收发都显示正常；
2.自己公司的板子，用的是串口SCIB，接的是sp3232电平转换芯片；但串口什么数据显示都没有；数据格式、波特率都设置正确的；各位给点思路？

（PS：板子上SCIBTXD引脚先接到一个si8422芯片，用来做隔离的，再接的电平转换芯片；
用示波器测量，程序里28335发送数据给PC时，SCIBTXD引脚有一个电平的跳变，但是经过si8422芯片后的SCIBTXD就没有波形的跳变了，会是这里的问题吗？）

只看该作者 · 2014-11-14 14:34

贴上程序：
void main(void)
{

Uint16 ReceivedChar;
char *msg;
InitSysCtrl();

InitScibGpio();
// InitXintf16Gpio();

DINT;

InitPieCtrl();

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

InitPieVectTable();

// Step 5. User specific code:

LoopCount = 0;
ErrorCount = 0;

scib_fifo_init();    // Initialize the SCI FIFO
scib_echoback_init();  // Initalize SCI for echoback

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

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

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

   // Wait for inc character
   while(ScibRegs.SCIFFRX.bit.RXFFST == 0) {} // ==1 break->receive BUF has new DATA
   msg = "  You sent: \0";
   scib_msg(msg);
      // Get all character
   do
   {
      ReceivedChar = ScibRegs.SCIRXBUF.all;
   // Echo character back
      scib_xmit(ReceivedChar);
}while(ScibRegs.SCIFFRX.bit.RXFFST != 0);

   LoopCount++;
}

}

// Test 1,SCIA  DLB, 8-bit word, baud rate 0x000F, default, 1 STOP bit, no parity
void scib_echoback_init()
{
// Note: Clocks were turned on to the SCIA peripheral
// in the InitSysCtrl() function

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

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

void scib_msg(char * msg)
{
int i;
i = 0;
while(msg[i] != '\0')
{
      scib_xmit(msg[i]);
      i++;
}
}

// Initalize the SCI FIFO
void scib_fifo_init()
{
//ScibRegs.SCIFFTX.all=0x8000;
ScibRegs.SCIFFTX.all=0xE040;
ScibRegs.SCIFFRX.all=0x204f;
ScibRegs.SCIFFCT.all=0x0; //禁止串口自动检测波特率
}