css_cmake_test/f2833x/examples/sci_echoback/Example_2833xSci_Echoback.c

//###########################################################################
//
// FILE:	Example_2833xSci_Echoback.c
//
// TITLE:	SCI Echo Back Example
//
//! \addtogroup f2833x_example_list
//! <h1>SCI Echo Back (sci_echoback)</h1>
//!
//!  This test receives and echo-backs data through the SCI-A port.
//!
//!  The PC application 'hypterterminal' can be used to view the data
//!  from the SCI and to send information to the SCI.  Characters received
//!  by the SCI port are sent back to the host.
//!
//!  \b Running \b the \b Application
//!  -# Configure hyperterminal:
//!  Use the included hyperterminal configuration file SCI_96.ht.
//!  To load this configuration in hyperterminal
//!    -# Open hyperterminal
//!    -# Go to file->open
//!    -# Browse to the location of the project and
//!       select the SCI_96.ht file.
//!  -# Check the COM port.
//!  The configuration file is currently setup for COM1.
//!  If this is not correct, disconnect (Call->Disconnect)
//!  Open the File-Properties dialog and select the correct COM port.
//!  -# Connect hyperterminal Call->Call
//!  and then start the 2833x SCI echoback program execution.
//!  -# The program will print out a greeting and then ask you to
//!  enter a character which it will echo back to hyperterminal.
//!
//! As is, the program configures SCI-A for 9600 baud with
//! SYSCLKOUT = 150MHz and LSPCLK = 37.5 MHz
//! or SYSCLKOUT = 100MHz and LSPCLK = 25.0 Mhz
//!
//!  \b Watch \b Variables \n
//!  - LoopCount - Number of characters sent
//!  - ErrorCount
//!
//! \b External \b Connections \n
//!  Connect the SCI-A port to a PC via a transceiver and cable.
//!  - GPIO28 is SCI_A-RXD (Connect to Pin3, PC-TX, of serial DB9 cable)
//!  - GPIO29 is SCI_A-TXD (Connect to Pin2, PC-RX, of serial DB9 cable)
//
//###########################################################################
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// $Release Date: $
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//
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// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
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// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
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//###########################################################################

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

//
// Function Prototypes
//
void scia_echoback_init(void);
void scia_fifo_init(void);
void scia_xmit(int a);
void scia_msg(char *msg);

//
// Globals
//
Uint16 LoopCount;
Uint16 ErrorCount;

//
// Main
//
void main(void)
{
    Uint16 ReceivedChar;
    char *msg;

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

    //
    // Step 2. Initialize 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(); Skipped for this example

    //
    // For this example, only init the pins for the SCI-A port.
    // This function is found in the DSP2833x_Sci.c file.
    //
    InitSciaGpio();

    //
    // 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();

    //
    // Step 4. Initialize all the Device Peripherals:
    // This function is found in DSP2833x_InitPeripherals.c
    //
    // InitPeripherals(); // Not required for this example

    //
    // Step 5. User specific code
    //
    LoopCount = 0;
    ErrorCount = 0;

    scia_fifo_init();	   // Initialize the SCI FIFO
    scia_echoback_init();  // Initialize SCI for echoback

    msg = "\r\n\n\nHello World!\0";
    scia_msg(msg);

    msg = "\r\nYou will enter a character, and the DSP will echo \
            it back! \n\0";
    scia_msg(msg);

    for(;;)
    {
        msg = "\r\nEnter a character: \0";
        scia_msg(msg);

        //
        // Wait for inc character
        //
        while(SciaRegs.SCIFFRX.bit.RXFFST !=1)
        {
            //
            // wait for XRDY =1 for empty state
            //
        }

        //
        // Get character
        //
        ReceivedChar = SciaRegs.SCIRXBUF.all;

        //
        // Echo character back
        //
        msg = "  You sent: \0";
        scia_msg(msg);
        scia_xmit(ReceivedChar);

        LoopCount++;
    }
}

//
// scia_echoback_init - Test 1,SCIA  DLB, 8-bit word, baud rate 0x000F, 
// default, 1 STOP bit, no parity
//
void 
scia_echoback_init()
{
    //
    // Note: Clocks were turned on to the SCIA peripheral
    // in the InitSysCtrl() function
    //
    
    // 1 stop bit,  No loopback, No parity,8 char bits,
    // async mode, idle-line protocol
    //
    SciaRegs.SCICCR.all =0x0007;
    
    //
    // enable TX, RX, internal SCICLK,
    // Disable RX ERR, SLEEP, TXWAKE
    //
    SciaRegs.SCICTL1.all =0x0003;
    SciaRegs.SCICTL2.all =0x0003;
    SciaRegs.SCICTL2.bit.TXINTENA =0;
    SciaRegs.SCICTL2.bit.RXBKINTENA =0;
#if (CPU_FRQ_150MHZ)
    SciaRegs.SCIHBAUD    =0x0001;  // 9600 baud @LSPCLK = 37.5MHz.
    SciaRegs.SCILBAUD    =0x00E7;
#endif
#if (CPU_FRQ_100MHZ)
    SciaRegs.SCIHBAUD    =0x0001;  // 9600 baud @LSPCLK = 20MHz.
    SciaRegs.SCILBAUD    =0x0044;
#endif
    SciaRegs.SCICTL1.all =0x0023;  // Relinquish SCI from Reset
}

//
// scia_xmit - Transmit a character from the SCI
//
void 
scia_xmit(int a)
{
    while (SciaRegs.SCIFFTX.bit.TXFFST != 0) 
    {
        
    }
    SciaRegs.SCITXBUF=a;
}

//
// scia_msg -
//
void 
scia_msg(char * msg)
{
    int i;
    i = 0;
    while(msg[i] != '\0')
    {
        scia_xmit(msg[i]);
        i++;
    }
}

//
// scia_fifo_init - Initialize the SCI FIFO
//
void 
scia_fifo_init()
{
    SciaRegs.SCIFFTX.all=0xE040;
    SciaRegs.SCIFFRX.all=0x204f;
    SciaRegs.SCIFFCT.all=0x0;
}

//
// End of File
//