example_281xsci_ffdlb.c

tms320f2812例子程序

//###########################################################################
//
// FILE:    Example_281xSci_FFDLB.c
//
// TITLE:   DSP281x Device SCI FIFO Digital Loop Back Test. 
//
// ASSUMPTIONS:
//
//          This program requires the DSP281x V1.00 header files.  
//          As supplied, this project is configured for "boot to H0" operation.
//
//          Other then boot mode pin configuration, no other hardware configuration
//          is required. 
//
// 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 for the number of characters sent
//                ErrorCount 
//		
//
//###########################################################################
//
// Original Author: S.S.
//
//  Ver | dd mmm yyyy | Who  | Description of changes
// =====|=============|======|===============================================
//  1.00| 11 Sep 2003 | L.H. | No change since previous version (v.58 Alpha)
//###########################################################################


#include "DSP281x_Device.h"
#include "DSP281x_Examples.h"

// 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(int);
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 DSP281x_SysCtrl.c file.
	InitSysCtrl();

// Step 2. Select GPIO for the device or for the specific application:
       // This function is found in the DSP281x_Gpio.c file.
       // InitGpio(); skip this as this is example selects the I/O for SCI in this file itself
    EALLOW;
    GpioMuxRegs.GPFMUX.all=0x0030;	// Select GPIOs to be Sci pins	 
                                    // Port F MUX - x000 0000 0011 0000
    EDIS;

// 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 DSP281x_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 DSP281x_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 DSP281x_PieVect.c.
      // This function populates the PIE vector table with pointers
      // to the shell ISR functions found in DSP281x_DefaultIsr.c.
	  InitPieVectTable();  

      // Enable CPU and PIE interrupts
      // This example function is found in the DSP281x_PieCtrl.c file.   
      EnableInterrupts();
	
// Step 4. Initialize all the Device Peripherals to a known state:
      // This function is found in DSP281x_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.RXFIFST !=1) { } // wait for XRDY =1 for empty state
  
       // Check received character
       ReceivedChar = SciaRegs.SCIRXBUF.all;			
       if(ReceivedChar != SendChar) error(1);

       // 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(int ErrorFlag)
{
      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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