【新人求助】28335使用SCI通信的问题

//###########################################################################

//

// FILE:    Example_2833xSci_FFDLB.c

//

// TITLE:   DSP2833x Device SCI FIFO Digital Loop Back Test.

//

// ASSUMPTIONS:

//

//    This program requires the DSP2833x 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 2833x 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:

//

//         GPIO87   GPIO86     GPIO85   GPIO84

//          XA15     XA14       XA13     XA12

//           PU       PU         PU       PU

//        ==========================================

//            1        1          1        1    Jump to Flash

//            1        1          1        0    SCI-A boot

//            1        1          0        1    SPI-A boot

//            1        1          0        0    I2C-A boot

//            1        0          1        1    eCAN-A boot

//            1        0          1        0    McBSP-A boot

//            1        0          0        1    Jump to XINTF x16

//            1        0          0        0    Jump to XINTF x32

//            0        1          1        1    Jump to OTP

//            0        1          1        0    Parallel GPIO I/O boot

//            0        1          0        1    Parallel XINTF boot

//            0        1          0        0    Jump to SARAM            <- "boot to SARAM"

//            0        0          1        1    Branch to check boot mode

//            0        0          1        0    Boot to flash, bypass ADC cal

//            0        0          0        1    Boot to SARAM, bypass ADC cal

//            0        0          0        0    Boot to SCI-A, bypass ADC cal

//                                              Boot_Table_End$

//

// DESCRIPTION:

//

//    This test uses the loopback test mode of the SCI module to send

//    characters starting with 0x00 through 0xFF.  The test will send

//    a character and then check the receive buffer for a correct match.

//

//          Watch Variables:

//                LoopCount      Number of characters sent

//                ErrorCount     Number of errors detected

//                SendChar       Character sent

//                ReceivedChar   Character recieved

//

//

//###########################################################################

//

// Original Author: S.S.

//

// $TI Release: 2833x/2823x Header Files and Peripheral Examples V133 $

// $Release Date: June 8, 2012 $

//###########################################################################





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



// Prototype statements for functions found within this file.

void scia_loopback_init(void);

void scia_fifo_init(void);

void scia_xmit(int a);

void error();

interrupt void scia_rx_isr(void);

interrupt void scia_tx_isr(void);



// Global counts used in this example

Uint16 LoopCount;

Uint16 ErrorCount;



void main(void)

{

    Uint16 SendChar;

    Uint16 ReceivedChar;



// Step 1. Initialize System Control registers, PLL, WatchDog, Clocks to default state:

// This function is found in the DSP2833x_SysCtrl.c file.

        InitSysCtrl();



// Step 2. Select GPIO for the device or for the specific application:

// This function is found in the DSP2833x_Gpio.c file.

// InitGpio(); skip this as this is example selects the I/O

// for SCI-A in this file itself

   InitSciGpio();



// Step 3. Initialize PIE vector table:

// The PIE vector table is initialized with pointers to shell Interrupt

// Service Routines (ISR).  The shell routines are found in DSP2833x_DefaultIsr.c.

// Insert user specific ISR code in the appropriate shell ISR routine in

// the DSP28_DefaultIsr.c file.



// Disable and clear all CPU interrupts:

        DINT;

        IER = 0x0000;

        IFR = 0x0000;



      // Initialize Pie Control Registers To Default State:

      // This function is found in the DSP2833x_PieCtrl.c file.

          // InitPieCtrl();  PIE is not used for this example



      // Initialize the PIE Vector Table To a Known State:

      // This function is found in DSP2833x_PieVect.c.

      // This function populates the PIE vector table with pointers

      // to the shell ISR functions found in DSP2833x_DefaultIsr.c.

          InitPieVectTable();



      // Enable CPU and PIE interrupts

      // This example function is found in the DSP2833x_PieCtrl.c file.

      EnableInterrupts();



// Step 4. Initialize all the Device Peripherals to a known state:

// This function is found in DSP2833x_InitPeripherals.c

// InitPeripherals(); skip this for SCI tests



// Step 5. User specific functions, Reassign vectors (optional), Enable Interrupts:



    LoopCount = 0;

    ErrorCount = 0;



    scia_fifo_init();           // Initialize the SCI FIFO

    scia_loopback_init();  // Initalize SCI for digital loop back



    // Note: Autobaud lock is not required for this example



    // Send a character starting with 0

    SendChar = 0;



// Step 6. Send Characters forever starting with 0x00 and going through

// 0xFF.  After sending each, check the recieve buffer for the correct value



        for(;;)

    {

       scia_xmit(SendChar);

       while(SciaRegs.SCIFFRX.bit.RXFFST !=1) { } // wait for RRDY/RXFFST =1 for 1 data available in FIFO



       // Check received character

       ReceivedChar = SciaRegs.SCIRXBUF.all;

       if(ReceivedChar != SendChar) error();



       // Move to the next character and repeat the test

       SendChar++;

       // Limit the character to 8-bits

       SendChar &= 0x00FF;

       LoopCount++;

    }



}





// Step 7. Insert all local Interrupt Service Routines (ISRs) and functions here:



void error()

{



      ErrorCount++;

//    asm("     ESTOP0");  // Uncomment to stop the test here

//    for (;;);



}



// Test 1,SCIA  DLB, 8-bit word, baud rate 0x000F, default, 1 STOP bit, no parity

void scia_loopback_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;

    SciaRegs.SCIHBAUD    =0x0000;

    SciaRegs.SCILBAUD    =0x000F;

        SciaRegs.SCICCR.bit.LOOPBKENA =1; // Enable loop back

        SciaRegs.SCICTL1.all =0x0023;     // Relinquish SCI from Reset

}



// Transmit a character from the SCI'

void scia_xmit(int a)

{

    SciaRegs.SCITXBUF=a;

}



// Initalize the SCI FIFO

void scia_fifo_init()

{

    SciaRegs.SCIFFTX.all=0xE040;

    SciaRegs.SCIFFRX.all=0x204f;

    SciaRegs.SCIFFCT.all=0x0;



}













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