//
//      Lab CAN_1  : TMS320F2812
//      (C) Frank Bormann
//
//###########################################################################
//
// FILE:    Lab_CAN_1.c
//
// TITLE:   DSP28 CAN - Transmission with the Zwickau-adapterboard
//
//          Jumper JP4 :  2-3  ( 120 Ohm enabled)
//          Jumper JP5 :  1-2  ; Jumper JP6 _ 1-2 ( highspeed transceiver SN


//
//          Aim of the test :
//          Transmit the status of the 8 switches from GPIO - Port B15...B8
//          repeat the transmission every second
//          Mailbox 5 is used for transmission
//          Identifier : 0x1000 0000
//          DLC =  1
//
//          Frequency Osscillator : 30MHz
//          PLLCR = 0xA   :  multiply by 5
//          SYSCLKOUT = CLKIN = 150MHz
//          Highspeed - Prescaler (HISPCP = 0x0001; div by 2 ) : 75 Mhz
//          Lowspeed - Prescaler (LOSPCP  = 0x0002; div by 4 ) : 37.5 Mhz
//###########################################################################
//
//  Ver | dd mmm yyyy | Who  | Description of changes
// =====|=============|======|===============================================
//  1.0 | 09 May 2003 | F.B. | Startup Version for Lab_CAN_1
//  2.0 | 27 Nov 2003 | F.B. | adapted to header-files Version 1.00
//      |             |      |
//###########################################################################

// CAUTION :  DSP281x_ECan.h  , Version 1.0 ( Hareesh) contains an error
// the byte field of struct  CANMDL_BYTES and CANMDH_BYTES
// have the wrong order ( Byte1 to 4)instead of Byte 4 to 1)
// MODIFY  :  inside DSP281x_ECan.h modify the two structures to :
// struct  CANMDL_BYTES {      // bits   description
//   Uint16      BYTE3:8;     // 31:24
//   Uint16      BYTE2:8;     // 23:16
//   Uint16      BYTE1:8;     // 15:8
//   Uint16      BYTE0:8;     // 7:0
// };
//
// struct  CANMDH_BYTES {      // bits   description
//   Uint16      BYTE7:8;     // 63:56
//   Uint16      BYTE6:8;     // 55:48
//   Uint16      BYTE5:8;     // 47:40
//   Uint16      BYTE4:8;     // 39:32
// };
//##########################################################################

#include "DSP28x_Project.h"


#define IDENTIFIER 0x10000000

// Prototype statements for functions found within this file.

void Gpio_select(void);
void delay_loop();
Uint16 loopcount =0;
// Global Variables

/* Create a shadow register structure for the CAN control registers. This is
 needed, since, only 32-bit access is allowed to these registers. 16-bit access
 to these registers could potentially corrupt the register contents. This is
 especially true while writing to a bit (or group of bits) among bits 16 - 31 */

struct  ECAN_REGS ECanaShadow;

main()
{
// Initialize System Control registers, PLL, WatchDog, Clocks to default state:
// This function is found in the DSP28_SysCtrl.c file.
    InitSysCtrl();

// Initialise the physical pins of the DSP
    Gpio_select();

/* Initialize the CAN module */
    InitECan();

/* Write to the MSGID field  */

    ECanaMboxes.MBOX5.MSGID.all     = IDENTIFIER;
    ECanaMboxes.MBOX5.MSGID.bit.IDE = 1;  // Extended Identifier

/* Configure Mailbox under test as a Transmit mailbox */

    ECanaShadow.CANMD.all = ECanaRegs.CANMD.all;
    ECanaShadow.CANMD.bit.MD5 = 0;
    ECanaRegs.CANMD.all = ECanaShadow.CANMD.all;

/* Enable Mailbox under test */

    ECanaShadow.CANME.all = ECanaRegs.CANME.all;
    ECanaShadow.CANME.bit.ME5 = 1;
    ECanaRegs.CANME.all = ECanaShadow.CANME.all;

/* Write to DLC field in Master Control reg */

    ECanaMboxes.MBOX5.MSGCTRL.bit.DLC = 1;
    ECanaMboxes.MBOX5.MDL.all = 0x00000005;
      ECanaMboxes.MBOX5.MDH.all = 0x00000005;
/* Begin transmitting */


      for(;;)
      {
          ECanaShadow.CANTRS.all = 0;
          ECanaShadow.CANTRS.bit.TRS5 = 1;             // Set TRS for mailbox under test
          ECanaRegs.CANTRS.all = ECanaShadow.CANTRS.all;

          do
           {
           ECanaShadow.CANTA.all = ECanaRegs.CANTA.all;
           } while(ECanaShadow.CANTA.bit.TA5 == 0 );   // Wait for TA5 bit to be set..


          ECanaShadow.CANTA.all = 0;
          ECanaShadow.CANTA.bit.TA5 = 1;               // Clear TA5
          ECanaRegs.CANTA.all = ECanaShadow.CANTA.all;

          loopcount ++;
       }
        asm(" ESTOP0");  // Stop here

}

void Gpio_select(void)
{
    EALLOW;
    GpioCtrlRegs.GPAMUX1.all=0; //PORT A IS THE can PORT
    GpioCtrlRegs.GPAMUX2.all=0;
    GpioCtrlRegs.GPBMUX1.all=0;
       GpioCtrlRegs.GPBMUX2.all=0;


    GpioCtrlRegs.GPAMUX2.bit.GPIO19 = 3; // setting gpio19 as CANTXA
    GpioCtrlRegs.GPAMUX2.bit.GPIO18 = 3;  // setting gpio18 as CANRXA

    GpioCtrlRegs.GPADIR.all=0;       // GPIO PORTs  as input
    GpioCtrlRegs.GPBDIR.all=0x00ff;  // GPIO Port B15-B8 input , B7-B0 output
    GpioCtrlRegs.GPCDIR.all=0;


    GpioCtrlRegs.GPAQSEL1.all=0;          // Set GPIO input qualifier values
    GpioCtrlRegs.GPAQSEL2.all=0;

    GpioCtrlRegs.GPBQSEL1.all=0;
        GpioCtrlRegs.GPBQSEL2.all=0;



    GpioDataRegs.GPBDAT.all = 0x0000;   // Switch off LED's ( B7...B0)

    EDIS;
}

void delay_loop()
{
    long      i;
    for (i = 0; i < 10000000; i++) {}
}