example_280xsci_echoback.c

DSP学习板上的例子程序包括 AD转换 CAN总线 SPI SCI

// TI File $Revision: /main/4 $
// Checkin $Date: May 19, 2005   16:55:18 $
// Modified by LSD_Hanbing to suit the LSD_EVM320F2801X, April 25,2007
//###########################################################################
//
// FILE:    Example_280xSci_Echoback.c
//
// TITLE:   DSP280x Device SCI Echoback. 
//
// ASSUMPTIONS:
//
//    This program requires the DSP280x header files.  
//    As supplied, this project is configured for "boot to SARAM" operation.
//
//    Connect the SCI-A port to a PC via a transciever and cable.  
//    The PC application 'hypterterminal' can be used to view the data
//    from the SCI and to send information to the SCI.  Characters recieved
//    by the SCI port are sent back to the host. 
//
//    As supplied, this project is configured for "boot to SARAM" 
//    operation.  The 280x Boot Mode table is shown below.  
//    For information on configuring the boot mode of an LSD_EVM320F2801X, 
//    please refer to the documentation included with the LSD_EVM320F2801X,  
//
//       Boot      GPIO18     GPIO29    GPIO34
//       Mode      SPICLKA    SCITXDA
//                  SCITXB
//       -------------------------------------
//       Flash       1          1        1
//       SCI-A       1          1        0
//       SPI-A       1          0        1
//       I2C-A       1          0        0
//       ECAN-A      0          1        1        
//       SARAM       0          1        0  <- "boot to SARAM"
//       OTP         0          0        1
//       I/0         0          0        0 
//
//
//
// DESCRIPTION:
//
//          
//    This test recieves and echo-backs data through the SCI-A port.  
//
//    1) Configure hyperterminal:
//       Use the included hyperterminal configuration file SCI_96.ht. 
//       To load this configuration in hyperterminal: file->open 
//       and then select the SCI_96.ht file. 
//    2) 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.
//    3) Connect hyperterminal Call->Call
//       and then start the 280x SCI echoback program execution. 
//    4) 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 = 60MHz and LSPCLK = 15Mhz.
//
// 
//    Watch Variables:
//       LoopCount for the number of characters sent
//       ErrorCount 
//		
//
//###########################################################################
// $TI Release: DSP280x, DSP2801x Header Files V1.41 $
// $Release Date: August 7th, 2006 $
//###########################################################################

#include "DSP280x_Device.h"     // DSP280x Headerfile Include File
#include "DSP280x_Examples.h"   // DSP280x Examples Include File

// Prototype statements for functions found within this file.
void scia_echoback_init(void);
void scia_fifo_init(void);	
void scia_xmit(int a);
void scia_msg(char *msg);

// Global counts used in this example
Uint16 LoopCount;
Uint16 ErrorCount; 

void main(void)
{

    Uint16 ReceivedChar;
    char *msg;
    
// Step 1. Initialize System Control:
// PLL, WatchDog, enable Peripheral Clocks
// This example function is found in the DSP280x_SysCtrl.c file.
   InitSysCtrl();

// Step 2. Initalize GPIO: 
// This example function is found in the DSP280x_Gpio.c file and
// illustrates how to set the GPIO to it's default state.
   // InitGpio(); Skipped for this example  
   EALLOW;
   GpioCtrlRegs.GPAMUX1.all = 0x0;    // GPIO pin
   GpioCtrlRegs.GPADIR.all = 0xFF;     // Output pin
   GpioDataRegs.GPADAT.all =0xFF;     // Close LEDs
   EDIS;

// For this example, only init the pins for the SCI-A port. 
// This function is found in the DSP280x_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 DSP280x_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 DSP280x_DefaultIsr.c.
// This function is found in DSP280x_PieVect.c.
   InitPieVectTable();

// Step 4. Initialize all the Device Peripherals:
// This function is found in DSP280x_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();  // Initalize 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++;
    }

} 	


// 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
    
 	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;  // 9600 baud @LSPCLK = 15MHz. 
    SciaRegs.SCILBAUD    =0x00C2;
	SciaRegs.SCICTL1.all =0x0023;  // Relinquish SCI from Reset 
}

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

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

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

                							
 
    


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