example_281xecanback2back.c

很好的DSP程序,对初学者很有帮助,快下哟

// TI File $Revision: /main/3 $
// Checkin $Date: May 1, 2007   10:01:47 $
//###########################################################################
//
// FILE:    Example_281xECanBack2Back.c
//
// TITLE:   DSP281x eCAN Back-to-back transmission and reception in
//          SELF-TEST mode
//
// 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 configuration, no other hardware configuration
//          is required.
//
// DESCRIPTION:
//
//          This test transmits data back-to-back at high speed without
//          stopping.
//          The received data is verified. Any error is flagged.
//          MBX0 transmits to MBX16, MBX1 transmits to MBX17 and so on....
//          This program illustrates the use of self-test mode
//
//###########################################################################
// $TI Release: $
// $Release Date: $
//###########################################################################

#include "DSP281x_Device.h"     // DSP281x Headerfile Include File
#include "DSP281x_Examples.h"   // DSP281x Examples Include File

// Prototype statements for functions found within this file.
void mailbox_check(int32 T1, int32 T2, int32 T3);
void mailbox_read(int16 i);

// Global variable for this example
Uint32  ErrorCount;
Uint32  MessageReceivedCount;

Uint32  TestMbox1 = 0;
Uint32  TestMbox2 = 0;
Uint32  TestMbox3 = 0;

void main(void)
{

    Uint16  j;

// eCAN control registers require read/write access using 32-bits.  Thus we
// will create a set of shadow registers for this example.  These shadow
// registers will be used to make sure the access is 32-bits and not 16.
   struct ECAN_REGS ECanaShadow;

// Step 1. Initialize System Control:
// PLL, WatchDog, enable Peripheral Clocks
// This example function is found in the DSP281x_SysCtrl.c file.
   InitSysCtrl();

// Step 2. Initalize GPIO:
// This example function is found in the DSP281x_Gpio.c file and
// illustrates how to set the GPIO to it's default state.
// InitGpio();  // Skipped for this example

// 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 DSP281x_PieCtrl.c file.
//   InitPieCtrl();	// Skipped for this example

// 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 DSP281x_DefaultIsr.c.
// This function is found in DSP281x_PieVect.c.
//   InitPieVectTable(); 	// Skipped for this example

// Step 4. Initialize all the Device Peripherals:
// This function is found in DSP281x_InitPeripherals.c
// InitPeripherals(); // Not required for this example

// Step 5. User specific code

    MessageReceivedCount = 0;
    ErrorCount = 0;
	InitECan();     // Initialize the eCAN module

    // Mailboxs can be written to 16-bits or 32-bits at a time
    // Write to the MSGID field of TRANSMIT mailboxes MBOX0 - 15
    ECanaMboxes.MBOX0.MSGID.all = 0x9555AAA0;
    ECanaMboxes.MBOX1.MSGID.all = 0x9555AAA1;
    ECanaMboxes.MBOX2.MSGID.all = 0x9555AAA2;
    ECanaMboxes.MBOX3.MSGID.all = 0x9555AAA3;
    ECanaMboxes.MBOX4.MSGID.all = 0x9555AAA4;
    ECanaMboxes.MBOX5.MSGID.all = 0x9555AAA5;
    ECanaMboxes.MBOX6.MSGID.all = 0x9555AAA6;
    ECanaMboxes.MBOX7.MSGID.all = 0x9555AAA7;
    ECanaMboxes.MBOX8.MSGID.all = 0x9555AAA8;
    ECanaMboxes.MBOX9.MSGID.all = 0x9555AAA9;
    ECanaMboxes.MBOX10.MSGID.all = 0x9555AAAA;
    ECanaMboxes.MBOX11.MSGID.all = 0x9555AAAB;
    ECanaMboxes.MBOX12.MSGID.all = 0x9555AAAC;
    ECanaMboxes.MBOX13.MSGID.all = 0x9555AAAD;
    ECanaMboxes.MBOX14.MSGID.all = 0x9555AAAE;
    ECanaMboxes.MBOX15.MSGID.all = 0x9555AAAF;

    // Write to the MSGID field of RECEIVE mailboxes MBOX16 - 31
    ECanaMboxes.MBOX16.MSGID.all = 0x9555AAA0;
    ECanaMboxes.MBOX17.MSGID.all = 0x9555AAA1;
    ECanaMboxes.MBOX18.MSGID.all = 0x9555AAA2;
    ECanaMboxes.MBOX19.MSGID.all = 0x9555AAA3;
    ECanaMboxes.MBOX20.MSGID.all = 0x9555AAA4;
    ECanaMboxes.MBOX21.MSGID.all = 0x9555AAA5;
    ECanaMboxes.MBOX22.MSGID.all = 0x9555AAA6;
    ECanaMboxes.MBOX23.MSGID.all = 0x9555AAA7;
    ECanaMboxes.MBOX24.MSGID.all = 0x9555AAA8;
    ECanaMboxes.MBOX25.MSGID.all = 0x9555AAA9;
    ECanaMboxes.MBOX26.MSGID.all = 0x9555AAAA;
    ECanaMboxes.MBOX27.MSGID.all = 0x9555AAAB;
    ECanaMboxes.MBOX28.MSGID.all = 0x9555AAAC;
    ECanaMboxes.MBOX29.MSGID.all = 0x9555AAAD;
    ECanaMboxes.MBOX30.MSGID.all = 0x9555AAAE;
    ECanaMboxes.MBOX31.MSGID.all = 0x9555AAAF;

    // Configure Mailboxes 0-15 as Tx, 16-31 as Rx
    // Since this write is to the entire register (instead of a bit
    // field) a shadow register is not required.
    ECanaRegs.CANMD.all = 0xFFFF0000;

    // Enable all Mailboxes */
    // Since this write is to the entire register (instead of a bit
    // field) a shadow register is not required.
    ECanaRegs.CANME.all = 0xFFFFFFFF;

    // Specify that 8 bits will be sent
    ECanaMboxes.MBOX0.MSGCTRL.bit.DLC = 8;
    ECanaMboxes.MBOX1.MSGCTRL.bit.DLC = 8;
    ECanaMboxes.MBOX2.MSGCTRL.bit.DLC = 8;
    ECanaMboxes.MBOX3.MSGCTRL.bit.DLC = 8;
    ECanaMboxes.MBOX4.MSGCTRL.bit.DLC = 8;
    ECanaMboxes.MBOX5.MSGCTRL.bit.DLC = 8;
    ECanaMboxes.MBOX6.MSGCTRL.bit.DLC = 8;
    ECanaMboxes.MBOX7.MSGCTRL.bit.DLC = 8;
    ECanaMboxes.MBOX8.MSGCTRL.bit.DLC = 8;
    ECanaMboxes.MBOX9.MSGCTRL.bit.DLC = 8;
    ECanaMboxes.MBOX10.MSGCTRL.bit.DLC = 8;
    ECanaMboxes.MBOX11.MSGCTRL.bit.DLC = 8;
    ECanaMboxes.MBOX12.MSGCTRL.bit.DLC = 8;
    ECanaMboxes.MBOX13.MSGCTRL.bit.DLC = 8;
    ECanaMboxes.MBOX14.MSGCTRL.bit.DLC = 8;
    ECanaMboxes.MBOX15.MSGCTRL.bit.DLC = 8;

    // Write to the mailbox RAM field of MBOX0 - 15
    ECanaMboxes.MBOX0.MDL.all = 0x9555AAA0;
    ECanaMboxes.MBOX0.MDH.all = 0x89ABCDEF;

    ECanaMboxes.MBOX1.MDL.all = 0x9555AAA1;
    ECanaMboxes.MBOX1.MDH.all = 0x89ABCDEF;

    ECanaMboxes.MBOX2.MDL.all = 0x9555AAA2;
    ECanaMboxes.MBOX2.MDH.all = 0x89ABCDEF;

    ECanaMboxes.MBOX3.MDL.all = 0x9555AAA3;
    ECanaMboxes.MBOX3.MDH.all = 0x89ABCDEF;

    ECanaMboxes.MBOX4.MDL.all = 0x9555AAA4;
    ECanaMboxes.MBOX4.MDH.all = 0x89ABCDEF;

    ECanaMboxes.MBOX5.MDL.all = 0x9555AAA5;
    ECanaMboxes.MBOX5.MDH.all = 0x89ABCDEF;

    ECanaMboxes.MBOX6.MDL.all = 0x9555AAA6;
    ECanaMboxes.MBOX6.MDH.all = 0x89ABCDEF;

    ECanaMboxes.MBOX7.MDL.all = 0x9555AAA7;
    ECanaMboxes.MBOX7.MDH.all = 0x89ABCDEF;

    ECanaMboxes.MBOX8.MDL.all = 0x9555AAA8;
    ECanaMboxes.MBOX8.MDH.all = 0x89ABCDEF;

    ECanaMboxes.MBOX9.MDL.all = 0x9555AAA9;
    ECanaMboxes.MBOX9.MDH.all = 0x89ABCDEF;

    ECanaMboxes.MBOX10.MDL.all = 0x9555AAAA;
    ECanaMboxes.MBOX10.MDH.all = 0x89ABCDEF;

    ECanaMboxes.MBOX11.MDL.all = 0x9555AAAB;
    ECanaMboxes.MBOX11.MDH.all = 0x89ABCDEF;

    ECanaMboxes.MBOX12.MDL.all = 0x9555AAAC;
    ECanaMboxes.MBOX12.MDH.all = 0x89ABCDEF;

    ECanaMboxes.MBOX13.MDL.all = 0x9555AAAD;
    ECanaMboxes.MBOX13.MDH.all = 0x89ABCDEF;

    ECanaMboxes.MBOX14.MDL.all = 0x9555AAAE;
    ECanaMboxes.MBOX14.MDH.all = 0x89ABCDEF;

    ECanaMboxes.MBOX15.MDL.all = 0x9555AAAF;
    ECanaMboxes.MBOX15.MDH.all = 0x89ABCDEF;

    // Configure the eCAN for self test mode
    // Enable the enhanced features of the eCAN.
    EALLOW;
    ECanaShadow.CANMC.all = ECanaRegs.CANMC.all;
    ECanaShadow.CANMC.bit.STM = 1;    // Configure CAN for self-test mode
    ECanaRegs.CANMC.all = ECanaShadow.CANMC.all;
    EDIS;

    // Begin transmitting
    while(1)
    {

       ECanaRegs.CANTRS.all = 0x0000FFFF;  // Set TRS for all transmit mailboxes
       while(ECanaRegs.CANTA.all != 0x0000FFFF ) {}  // Wait for all TAn bits to be set..
       ECanaRegs.CANTA.all = 0x0000FFFF;   // Clear all TAn
       MessageReceivedCount++;

       //Read from Receive mailboxes and begin checking for data */
       for(j=0; j<16; j++)         // Read & check 16 mailboxes
       {
          mailbox_read(j);         // This func reads the indicated mailbox data
          mailbox_check(TestMbox1,TestMbox2,TestMbox3); // Checks the received data
       }
    }
}

// This function reads out the contents of the indicated
// by the Mailbox number (MBXnbr).
void mailbox_read(int16 MBXnbr)
{
   volatile struct MBOX *Mailbox;
   Mailbox = &ECanaMboxes.MBOX0 + MBXnbr;
   TestMbox1 = Mailbox->MDL.all; // = 0x9555AAAn (n is the MBX number)
   TestMbox2 = Mailbox->MDH.all; // = 0x89ABCDEF (a constant)
   TestMbox3 = Mailbox->MSGID.all;// = 0x9555AAAn (n is the MBX number)

} // MSGID of a rcv MBX is transmitted as the MDL data.


void mailbox_check(int32 T1, int32 T2, int32 T3)
{
    if((T1 != T3) || ( T2 != 0x89ABCDEF))
    {
       ErrorCount++;
    }
}


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

/* Note:
As indicated in the 281x device errata (SPRZ193), double-reads/double writes should be
employed for accesses to the mailbox RAM & LAM/MOTO/MOTS areas. Note, however, that the
errata is applicable only if the mailbox RAM & LAM/MOTO/MOTS areas are accessed at the
same time. The header file example operates in self-test mode, with no possibility of
a contention. Hence, the workaround is not implemented. When eCAN is communicating with
another node in non self-test mode), the workaround must be incorporated.
*/