[参考译文] TMS320F28027：使用28027的 SCI 通信

尊敬的 Sachin：

您能否使用默认示例和电路板进行测试、看看它是否起作用？

此致、

文斯

您好，Vince，

我运行了 带中断的 SCI 环回的默认示例。 手表寄存器正确显示了 sdataA 和 rdataA 的值。 我使用 GPIO 28 29和 GND 进行连接。 不过、在 ESP32中未收到任何信息。 我正在附加代码。 波特率为9600。 我使用的是 TMS320F28027的 Lauchpad。 还有没有其他事情要做

// TI File $Revision: /main/4 $
// Checkin $Date: October 6, 2010   14:43:12 $
//###########################################################################
//
// FILE:   Example_2802xSci_FFDLB_int.c
//
// TITLE:  DSP2802x Device SCI Digital Loop Back porgram.
//
//
// ASSUMPTIONS:
//
//    This program requires the DSP2802x header files.
//
//    This program uses the internal loop back test mode of the peripheral.
//    Other then boot mode pin configuration, no other hardware configuration
//    is required.
//
//    As supplied, this project is configured for "boot to SARAM"
//    operation.  The 2802x Boot Mode table is shown below.
//    For information on configuring the boot mode of an eZdsp,
//    please refer to the documentation included with the eZdsp,
//
//    $Boot_Table
//    While an emulator is connected to your device, the TRSTn pin = 1,
//    which sets the device into EMU_BOOT boot mode. In this mode, the
//    peripheral boot modes are as follows:
//
//      Boot Mode:   EMU_KEY        EMU_BMODE
//                   (0xD00)	     (0xD01)
//      ---------------------------------------
//      Wait		 !=0x55AA        X
//      I/O		     0x55AA	         0x0000
//      SCI		     0x55AA	         0x0001
//      Wait 	     0x55AA	         0x0002
//      Get_Mode	 0x55AA	         0x0003
//      SPI		     0x55AA	         0x0004
//      I2C		     0x55AA	         0x0005
//      OTP		     0x55AA	         0x0006
//      Wait		 0x55AA	         0x0007
//      Wait		 0x55AA	         0x0008
//      SARAM		 0x55AA	         0x000A	  <-- "Boot to SARAM"
//      Flash		 0x55AA	         0x000B
//	    Wait		 0x55AA          Other
//
//   Write EMU_KEY to 0xD00 and EMU_BMODE to 0xD01 via the debugger
//   according to the Boot Mode Table above. Build/Load project,
//   Reset the device, and Run example
//
//   $End_Boot_Table
//
//   Assumes the device has both SCI-A and SCI-B peripherals.
//
// DESCRIPTION:
//
//    This program is a SCI example that uses the internal loopback of
//    the peripheral.  Both interrupts and the SCI FIFOs are used.
//
//    A stream of data is sent and then compared to the recieved stream.
//
//    The SCI-A sent data looks like this:
//    00 01
//    01 02
//    02 03
//    ....
//    FE FF
//    FF 00
//    etc..
//
//
//
//    The pattern is repeated forever.
//
//    Watch Variables:
//       sdataA             Data being sent
//       rdataA             Data received
//       rdata_pointA       Keep track of where we are in the datastream
//                         This is used to check the incoming data
//###########################################################################
// Original Source by S.D.
//
// $TI Release: 2802x C/C++ Header Files and Peripheral Examples V1.29 $
// $Release Date: January 11, 2011 $
//###########################################################################

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

#define CPU_FREQ 	40E6        // Default = 40 MHz. Change to 60E6 for 60 MHz devices
#define LSPCLK_FREQ CPU_FREQ/4
#define SCI_FREQ 	100E3
#define SCI_PRD 	(LSPCLK_FREQ/(SCI_FREQ*8))-1

// Prototype statements for functions found within this file.
interrupt void sciaTxFifoIsr(void);
interrupt void sciaRxFifoIsr(void);
interrupt void scibTxFifoIsr(void);
interrupt void scibRxFifoIsr(void);
void scia_fifo_init(void);
void scib_fifo_init(void);
void error(void);

// Global variables
Uint16 sdataA[2];    // Send data for SCI-A
Uint16 rdataA[2];    // Received data for SCI-A
Uint16 rdata_pointA; // Used for checking the received data

void main(void)
{
   Uint16 i;

// 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();
// Setup only the GP I/O only for SCI-A and SCI-B functionality
// This function is found in DSP2802x_Sci.c
   InitSciGpio();

// 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();

// Interrupts that are used in this example are re-mapped to
// ISR functions found within this file.
   EALLOW;	// This is needed to write to EALLOW protected registers
   PieVectTable.SCIRXINTA = &sciaRxFifoIsr;
   PieVectTable.SCITXINTA = &sciaTxFifoIsr;
   EDIS;   // This is needed to disable write to EALLOW protected registers

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

// Step 5. User specific code, enable interrupts:

// Init send data.  After each transmission this data
// will be updated for the next transmission
   for(i = 0; i<2; i++)
   {
      sdataA[i] = i;
   }

   rdata_pointA = sdataA[0];
// Enable interrupts required for this example
   PieCtrlRegs.PIECTRL.bit.ENPIE = 1;   // Enable the PIE block
   PieCtrlRegs.PIEIER9.bit.INTx1=1;     // PIE Group 9, INT1
   PieCtrlRegs.PIEIER9.bit.INTx2=1;     // PIE Group 9, INT2
   IER = 0x100;	// Enable CPU INT
   EINT;

// Step 6. IDLE loop. Just sit and loop forever (optional):
	for(;;);

}

void error(void)
{
    asm("     ESTOP0"); // Test failed!! Stop!
    for (;;);
}

interrupt void sciaTxFifoIsr(void)
{
    Uint16 i;
    for(i=0; i< 2; i++)
    {
 	   //SciaRegs.SCITXBUF=sdataA[i];     // Send data
        SciaRegs.SCITXBUF=100;
	}

    for(i=0; i< 2; i++)                 //Increment send data for next cycle
    {
 	   //sdataA[i] = (sdataA[i]+1) & 0x00FF;
        sdataA[i] = 100;
	}

	SciaRegs.SCIFFTX.bit.TXFFINTCLR=1;	// Clear SCI Interrupt flag
	PieCtrlRegs.PIEACK.all|=0x100;      // Issue PIE ACK
}

interrupt void sciaRxFifoIsr(void)
{
    Uint16 i;
	for(i=0;i<2;i++)
	{
	   rdataA[i]=SciaRegs.SCIRXBUF.all;	 // Read data
	}
	for(i=0;i<2;i++)                     // Check received data
	{
	   if(rdataA[i] != ( (rdata_pointA+i) & 0x00FF) ) error();
	}
	rdata_pointA = (rdata_pointA+1) & 0x00FF;

	SciaRegs.SCIFFRX.bit.RXFFOVRCLR=1;   // Clear Overflow flag
	SciaRegs.SCIFFRX.bit.RXFFINTCLR=1;   // Clear Interrupt flag

	PieCtrlRegs.PIEACK.all|=0x100;       // Issue PIE ack
}

void scia_fifo_init()
{
   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 =1;
   SciaRegs.SCICTL2.bit.RXBKINTENA =1;
   SciaRegs.SCIHBAUD    =0x0000;  // 9600 baud @LSPCLK = 15MHz (60 MHz SYSCLK).
   SciaRegs.SCILBAUD    =0x00C2;
   SciaRegs.SCICCR.bit.LOOPBKENA =1; // Enable loop back
   SciaRegs.SCIFFTX.all=0xC022;
   SciaRegs.SCIFFRX.all=0x0022;
   SciaRegs.SCIFFCT.all=0x00;

   SciaRegs.SCICTL1.all =0x0023;     // Relinquish SCI from Reset
   SciaRegs.SCIFFTX.bit.TXFIFOXRESET=1;
   SciaRegs.SCIFFRX.bit.RXFIFORESET=1;

}

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

在继续中、如果我使用 SCI_Echoback programm 示例、并将28027的 GPIO 28 29连接到 ESP32 Rx TX 引脚以及两个控制器的接地端。

并将行修改为  

 SciaRegs.SCITXBUF=200；

以传输值200。

尊敬的 Sachin：

您能否提供 C2000 TX 引脚的示波器捕获？ 想知道这是否可能是硬件问题。

此致、

文斯