Fifo SCI Receive Interrupt in TMS320F28035

Hi,

I have 2 problems when using SCI:

My platform is "Multi-Axis DMC EVM - F28035".

Also, I need duplex transmission & interrupt driven & FIFO, the F28035 standard example code - "(ver.1.21) scia_loopback_interrupts" is adopted as my code base.

1. When 2400bps(BRR=3124, LSPCLK_DIV=0), or 115200bps(BRR=10, LSPCLK_DIV=3),  are set, the hyperterminal shows wrong characters.

But when I use 57600(12,5), it goes well.

2. The following code snippet is identical to, except where I marked "^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^" where I tried to disable TX, & disable loopback.

===> in order to see whether or not RX interrupts generates while I input characters via hyperterminal. ====> Of course, no RX interrupts generated.

Would anyone please help me to point out that where can I correct the mis-configurations to let it work.

Thanks a lot.

Ken.

#define CPU_FREQ    60E6
#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 DSP2803x_SysCtrl.c file.
   InitSysCtrl();

// Step 2. Initalize GPIO:
// This example function is found in the DSP2803x_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 DSP2803x_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 DSP2803x_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 DSP2803x_DefaultIsr.c.
// This function is found in DSP2803x_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;

 //^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ added the following line, to set to 57600bps^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

SysCtrlRegs.LOSPCP.bit.LSPCLK=0x05;

//^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

   EDIS;   // This is needed to disable write to EALLOW protected registers

// Step 4. Initialize all the Device Peripherals:
// This function is found in DSP2803x_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
    }

    for(i=0; i< 2; 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<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

//^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ commented the following line, to turn off TX int ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
//   SciaRegs.SCICTL2.bit.TXINTENA =1;

//^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

   SciaRegs.SCICTL2.bit.RXBKINTENA =1;
   SciaRegs.SCIHBAUD = 0x0000;

//^^^^^^^^^^^^^^^^^^^^^^^use this line rather than the another to set to 57600bps^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

 SciaRegs.SCILBAUD = 12;
///////////////   SciaRegs.SCILBAUD = SCI_PRD;

//^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

//^^^^^^^^^^^^^^^^^^^^^^^^^^ commented the following 2 lines, for turning off LOOPBACK ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
//   SciaRegs.SCICCR.bit.LOOPBKENA =1; // Enable loop back
//   SciaRegs.SCIFFTX.all=0xC022;

 //^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ added the following line, to turn off TX FIFO int ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

SciaRegs.SCIFFTX.all=0xC002;

//^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

   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;

}