F28335 Experimenters kit serial communication problem

// TI File $Revision: /main/2 $
// Checkin $Date: July 30, 2009   18:45:28 $
//###########################################################################
//
// FILE:   Example_2833xSci_FFDLB_int.c
//
// TITLE:  DSP2833x Device SCI Digital Loop Back porgram.
//
//
// 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 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 02 03 04 05 06 07
//    01 02 03 04 05 06 07 08
//    02 03 04 05 06 07 08 09
//    ....
//    FE FF 00 01 02 03 04 05
//    FF 00 01 02 03 04 05 06
//    etc..
//
//
//    The SCI-B sent data looks like this:
//    FF FE FD FC FB FA F9 F8
//    FE FD FC FB FA F9 F8 F7
//    FD FC FB FA F9 F8 F7 F6
//    ....
//    01 00 FF FE FD FC FB FA
//    00 FF FE FD FC FB FA F9
//    etc..
//
//    Both patterns are repeated forever.
//
//    Watch Variables:
//
//       SCI-A           SCI-B
//       ----------------------
//       sdataA          sdataB           Data being sent
//       rdataA          rdataB           Data received
//       rdata_pointA    rdata_pointB     Keep track of where we are in the datastream
//                                        This is used to check the incoming data
//###########################################################################
// Original Source by S.D.
//
// $TI Release: DSP2833x/DSP2823x C/C++ Header Files V1.31 $
// $Release Date: August 4, 2009 $
//###########################################################################



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

#define CPU_FREQ 	 150E6
#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[8];    // Send data for SCI-A
Uint16 sdataB[8];    // Send data for SCI-B
Uint16 rdataA[8];    // Received data for SCI-A
Uint16 rdataB[8];    // Received data for SCI-A
Uint16 rdata_pointA; // Used for checking the received data
Uint16 rdata_pointB;


void main(void)
{
   Uint16 i;

// Step 1. Initialize System Control:
// PLL, WatchDog, enable Peripheral Clocks
// This example function is found in the DSP2833x_SysCtrl.c file.
   InitSysCtrl();

// Step 2. Initalize GPIO:
// This example function is found in the DSP2833x_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 DSP2833x_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 DSP2833x_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 DSP2833x_DefaultIsr.c.
// This function is found in DSP2833x_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;
   PieVectTable.SCIRXINTB = &scibRxFifoIsr;
   PieVectTable.SCITXINTB = &scibTxFifoIsr;
   EDIS;   // This is needed to disable write to EALLOW protected registers


// Step 4. Initialize all the Device Peripherals:
// This function is found in DSP2833x_InitPeripherals.c
// InitPeripherals(); // Not required for this example
   scia_fifo_init();  // Init SCI-A
   scib_fifo_init();  // Init SCI-B

// 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<8; i++)
   {
      sdataA[i] = i;
   }

   for(i = 0; i<8; i++)
   {
      sdataB[i] = 0xFF - i;
   }

   rdata_pointA = sdataA[0];
   rdata_pointB = sdataB[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
   PieCtrlRegs.PIEIER9.bit.INTx3=1;     // PIE Group 9, INT3
   PieCtrlRegs.PIEIER9.bit.INTx4=1;     // PIE Group 9, INT4
   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< 8; i++)
    {
 	   SciaRegs.SCITXBUF=sdataA[i];     // Send data
	}

    for(i=0; i< 8; i++)                 //Increment send data for next cycle
    {
 	   sdataA[i] = (sdataA[i]+1) & 0x00FF;
	}

	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<8;i++)
	{
	   rdataA[i]=SciaRegs.SCIRXBUF.all;	 // Read data
	}
	for(i=0;i<8;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;
   SciaRegs.SCILBAUD = SCI_PRD;
   SciaRegs.SCICCR.bit.LOOPBKENA =1; // Enable loop back
   SciaRegs.SCIFFTX.all=0xC028;
   SciaRegs.SCIFFRX.all=0x0028;
   SciaRegs.SCIFFCT.all=0x00;

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


}

interrupt void scibTxFifoIsr(void)
{
    Uint16 i;
    for(i=0; i< 8; i++)
    {
 	   ScibRegs.SCITXBUF=sdataB[i];     // Send data
	}

    for(i=0; i< 8; i++)                 //Increment send data for next cycle
    {
 	   sdataB[i] = (sdataB[i]-1) & 0x00FF;
	}

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

interrupt void scibRxFifoIsr(void)
{
    Uint16 i;
	for(i=0;i<8;i++)
	{
	   rdataB[i]=ScibRegs.SCIRXBUF.all;	 // Read data
	}
	for(i=0;i<8;i++)                     // Check received data
	{
	   if(rdataB[i] != ( (rdata_pointB-i) & 0x00FF) ) error();
	}
	rdata_pointB = (rdata_pointB-1) & 0x00FF;

	ScibRegs.SCIFFRX.bit.RXFFOVRCLR=1;  // Clear Overflow flag
	ScibRegs.SCIFFRX.bit.RXFFINTCLR=1; 	// Clear Interrupt flag
	PieCtrlRegs.PIEACK.all|=0x100;  	// Issue PIE ack
}

void scib_fifo_init()
{
   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.bit.TXINTENA =1;
   ScibRegs.SCICTL2.bit.RXBKINTENA =1;
   ScibRegs.SCIHBAUD    =0x0000;
   ScibRegs.SCILBAUD    =SCI_PRD;
   ScibRegs.SCICCR.bit.LOOPBKENA =1; // Enable loop back
   ScibRegs.SCIFFTX.all=0xC028;
   ScibRegs.SCIFFRX.all=0x0028;
   ScibRegs.SCIFFCT.all=0x00;

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

}

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