2812 SCI自动波特率检测

只看该作者 · 2014-1-20 14:54

如题，

这两天弄SCi自动波特率检测程序，SCIB做主设备 SCIA 做从设备，利用SCIA的接收中断进行数据回发，和相应的位清除操作，结果发现ABD 一直不会置位，程序一直在重复发送“A”,但是SCIA的接收中断只能进入一次，且接收的数据是0X00ff,而不是b所发送的"A",

希望有相关经验的人提示一下，出现这种问题的是什么？？帮忙分析下

还有就是我的板子吧SCI转换为了422 接口，连接我用示波器看过了，应该没有问题，B能发送出相应的数据，也能进A的相应管脚，但是A不能回发，也就是A的SciaRegs.SCIRXBUF.bit.RXDT没有接收到的数据不是“A”

感激不尽。。。

2万 · 2014-1-20 16:24

自动波特率检测你是在硬件仿真下做的还是烧写后
首先建议你：如果在硬件仿真下如果不行就reset一下CPU 然后重新下载一次试试
如果是烧写后测试我发现第一次不会自动识别成功然后复位一下硬件然后重新启动之后
就可以自动识别成功这可能是DSP的一个小bug

2万 · 2014-1-20 16:28

供你参考
void AutobaudLock(void)
{
SciaRegs.SCICTL1.bit.SWRESET = 0; //软复位
SciaRegs.SCICTL1.bit.SWRESET = 1; //使能SCI

// 波特率寄存器必须设置>= 1
SciaRegs.SCIHBAUD = 0;
SciaRegs.SCILBAUD = 1;

SciaRegs.SCIFFCT.bit.ABDCLR = 1; //清除ABD位
SciaRegs.SCIFFCT.bit.CDC = 1; //使能自动波特率侦测
}

2万 · 2014-1-20 16:29

interrupt void SCITXINTA_ISR(void)    // SCI-A
{
unsigned char ReceivedAChar;
DINT;//关闭总中断

//自动侦测波特率处理
if(SciaRegs.SCIFFCT.bit.ABD == 1)
   {
SciaRegs.SCIFFCT.bit.ABDCLR = 1; //清除ABD
      SciaRegs.SCIFFCT.bit.CDC = 0; //禁止自动波特率侦测
      ReceivedAChar = SciaRegs.SCIRXBUF.all;
SciaRegs.SCIFFRX.bit.RXFFINTCLR = 1;//清除中断标志位
SciaRegs.SCIFFRX.bit.RXFIFORESET=0; //将FIFO指针复位为0
SciaRegs.SCIFFRX.bit.RXFIFORESET=1; //退出复位状态
      if(ReceivedAChar == 'A')
{
Send_String_SCIA("right!");// Autobaud
SciaRegs.SCIFFRX.bit.RXFFIENA = 1;// 使能SCIA FIFO接收中断
connect_right = 1;
}
      else
      {
      Send_String_SCIA("wrong!");  // Autobaud
connect_right = 0;
}
   }

SciaRegs.SCIFFRX.bit.RXFFINTCLR = 1;//清除中断标志位
PieCtrl.PIEACK.all |= M_INT9; //响应中断
EINT; //开总中断
}

只看该作者 · 2014-1-20 17:41

zhangmangui 发表于 2014-1-20 16:24
自动波特率检测你是在硬件仿真下做的还是烧写后
首先建议你：如果在硬件仿真下如果不行就reset一下 ...

恩我是在硬件仿真模式下，我刚以为是硬件本身的问题，所以我把自检波特率给屏蔽了，就用B给A发，发现是可以的，谢谢斑竹我在看看。。。

2万 · 2014-1-20 18:46

raoxianbin 发表于 2014-1-20 17:41
恩我是在硬件仿真模式下，我刚以为是硬件本身的问题，所以我把自检波特率给屏蔽了，就用B给A发，发现 ...

什么时候有时间给大家开个专题自动波特率侦测的

只看该作者 · 2014-1-20 18:48

zhangmangui 发表于 2014-1-20 16:29
interrupt void SCITXINTA_ISR(void) // SCI-A
{
unsigned char ReceivedAChar;

搞定了，多谢斑竹回答，好像是一个在中断里，最先没有关闭总中断，但是感觉这也不是什么问题

把代码贴出来吧

#include "DSP28_Device.h"
#include "DSP28_Globalprototypes.h"

#define BAUDSTEP 10
void scia_init(void);
void scib_init(void);
void scia_xmit(int a);
void scib_xmit(int a);
void scia_AutobaudLock(void);
void error(int);
interrupt void rxaint_isr(void);

Uint16 LoopCount;

Uint16 ReceivedCount;
Uint16 ErrorCount;
Uint16 SendChar;
Uint16 ReceivedAChar;
Uint16 ReceivedBChar;
Uint16 BRRVal;
Uint16 Buff[10] = {0x55, 0xAA, 0xF0, 0x0F, 0x00, 0xFF, 0xF5, 0x5F, 0xA5, 0x5C};

void main(void)
{
Uint16 i;

InitSysCtrl();

EALLOW;
GpioMuxRegs.GPFMUX.all=0x0030; // Select GPIOs to be Scia pins
                  GpioMuxRegs.GPGMUX.all=0x0030; // Select GPIOs to be Scib pins
                                    EDIS;

InitPieCtrl();

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

InitPieVectTable();

EALLOW;       // This is needed to write to EALLOW protected registers
PieVectTable.RXAINT = &rxaint_isr;
EDIS;
scia_init();    // Initalize SCIA
scib_init();    // Initalize SCIB

LoopCount = 0;
ErrorCount = 0;
ReceivedCount=0;
SendChar=0;

PieCtrl.PIEIER9.all = 0x0001; // Enable all SCIA RXINT interrupt  SCI B don't enable
IER |= 0x0100;          // enable PIEIER9, and INT9  cpu  intertupt
EINT;

   for (BRRVal = 0x00f3; BRRVal < (Uint32)0xFFFF; BRRVal+=BAUDSTEP)
{

   //SCIB has a known baud rate.  SCIA will autobaud to match
   ScibRegs.SCIHBAUD = (BRRVal >> 8);//host
   ScibRegs.SCILBAUD = (BRRVal);

           scia_AutobaudLock();

// scib_xmit('A');
   while(ScibRegs.SCIRXST.bit.RXRDY != 1) { }
      ReceivedBChar = 0;
      ReceivedBChar =  ScibRegs.SCIRXBUF.bit.RXDT;
// ReceivedBChar =  ScibRegs.SCIRXBUF.all
   if(ReceivedBChar != 'A')
      {
         error(0);
      }

              for(i= 0; i<=9; i++)
      {
      SendChar = Buff;
      scib_xmit(SendChar);

      while(ScibRegs.SCIRXST.bit.RXRDY != 1)
      {
            asm(" NOP");
      }
      ReceivedBChar = 0;
      ReceivedBChar =  ScibRegs.SCIRXBUF.bit.RXDT;
      if(ReceivedBChar != SendChar)
      error(1);
      }

} // Repeat for next BRR setting

      for(;;)
{
   asm(" NOP");
}

}

interrupt void rxaint_isr(void)    // SCI-A
{
  // Insert ISR Code here

   DINT;//关闭总中断
// If we were autobaud detecting, we must clear CDC
  if(SciaRegs.SCIFFCT.bit.ABD == 1)
{
   SciaRegs.SCIFFCT.bit.ABDCLR = 1;
   SciaRegs.SCIFFCT.bit.CDC = 0;// Check received character - should be 'A'  IF not "a" the program will into the
      //scia_AutobaudLock()

   ReceivedAChar = 0;
// ScibRegs.SCIRXBUF.bit.RXDT='A';
   ReceivedAChar =  SciaRegs.SCIRXBUF.bit.RXDT;
   // ReceivedAChar = SciaRegs.SCIRXBUF.all;
   if(ReceivedAChar != 'A')
   {
      error(2);
   }
   else scia_xmit(ReceivedAChar);
  }

// This was not autobaud detect
else
{
   // Check received character against sendchar
   ReceivedAChar = 0;
   ReceivedAChar = SciaRegs.SCIRXBUF.all;

   if(ReceivedAChar != SendChar)
   {
      error(3);
   }
   else scia_xmit(ReceivedAChar);
}

SciaRegs.SCIFFRX.bit.RXFFINTCLR = 1; // clear Receive interrupt flag  ABD SRT 1 will  cause FIFO中断（TXINT）。
//SciaRegs.SCIFFCT.bit.CDC = 0;
SciaRegs.SCIFFRX.bit.RXFIFORESET=0;
SciaRegs.SCIFFRX.bit.RXFIFORESET=1;
ReceivedCount++;

PieCtrl.PIEACK.all = PIEACK_GROUP9;
EINT;
}

void error(int ErrorFlag)
{
   ErrorCount++;
   /*asm("    ESTOP0");             // Uncomment to stop the test here 出错时，则停止运行
   for (;;);*/

}

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

// Reset FIFO's
SciaRegs.SCIFFTX.all=0x8000;

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.SCIHBAUD = 0;
//SciaRegs.SCILBAUD = 0xF3;
SciaRegs.SCICTL2.bit.RXBKINTENA =1;
SciaRegs.SCICTL1.all =0x0023;    // Relinquish SCI from Reset

}

void scib_init()
{
      ScibRegs.SCIFFTX.all=0x8000;

// 1 stop bit, No parity, 8-bit character
// No loopback
ScibRegs.SCICCR.all = 0x0007;

// Enable TX, RX, Use internal SCICLK
ScibRegs.SCICTL1.all = 0x0003;
   // SCIB has a known baud rate.  SCIA will autobaud to match
      //ScibRegs.SCIHBAUD = 0;
      //ScibRegs.SCILBAUD = 0xf3;

// Disable RxErr, Sleep, TX Wake,
// Diable Rx Interrupt, Tx Interrupt
ScibRegs.SCICTL2.all = 0x0000;

// Relinquish SCI-A from reset
ScibRegs.SCICTL1.all = 0x0023;//重启SCI

//return;
}

// Transmit a character from the SCI-A'
void scia_xmit(int a)
{
SciaRegs.SCITXBUF=a;
}

// Transmit a character from the SCI-B'
void scib_xmit(int a)
{
ScibRegs.SCITXBUF=a;
}

void scia_AutobaudLock()
{
Uint32 i;
SciaRegs.SCICTL1.bit.SWRESET = 0;
SciaRegs.SCICTL1.bit.SWRESET = 1;

// Must prime baud register with >= 1
SciaRegs.SCIHBAUD = 0;
SciaRegs.SCILBAUD = 1;

      SciaRegs.SCIFFCT.bit.ABDCLR = 1;
SciaRegs.SCIFFCT.bit.CDC = 1;

      while(SciaRegs.SCIFFCT.bit.CDC== 1)
{
         for(i = 1; i<= 0x0FFFFFF; i++)
   {
         // asm("    NOP");
   }

   if(SciaRegs.SCIFFCT.bit.CDC == 1)
   // for(;;)
         scib_xmit('A');  // host transmits 'A'

}

//return;
}

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

谢谢斑竹了。。

只看该作者 · 2014-1-20 18:49

zhangmangui 发表于 2014-1-20 18:46
什么时候有时间给大家开个专题自动波特率侦测的

呵静等斑竹开题。。。

2万 · 2014-1-20 18:52

raoxianbin 发表于 2014-1-20 18:48
搞定了，多谢斑竹回答，好像是一个在中断里，最先没有关闭总中断，但是感觉这也不是什么问题

把代码贴出 ...

好的谢谢分享

2812 SCI自动波特率检测

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