void main()
{
unsigned int kk, t;
/* 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;
struct ECAN_REGS ECanbShadow;
// Step 1. Initialize System Control:
// PLL, WatchDog, enable Peripheral Clocks
// This example function is found in the DSP2833x_SysCtrl.c file.
InitSysCtrl();
// Step 2. Initalize 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
// Just initalize eCAN pins for this example
// This function is in DSP2833x_ECan.c
// InitECanGpio();
InitECanbGpio();
// Step 3. Clear all interrupts and initialize PIE vector table:
// Disable CPU interrupts
DINT;
// Initialize the 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;
ECanbShadow.CANTRS.all = 0;
ECanbShadow.CANTRS.bit.TRS25 = 1; // Set TRS for mailbox under test
ECanbRegs.CANTRS.all = ECanbShadow.CANTRS.all;
kk = 0;
do
{
kk = kk + 1;
ECanbShadow.CANTA.all = ECanbRegs.CANTA.all;
} while((ECanbShadow.CANTA.bit.TA25 == 0 ) && (kk < 10000)); // Wait for TA5 bit to be set..
void InitECanb(void) // Initialize eCAN-B module
{
/* 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 or return
false data. This is especially true while writing to/reading from a bit
(or group of bits) among bits 16 - 31 */
struct ECAN_REGS ECanbShadow;
EALLOW; // EALLOW enables access to protected bits
/* Configure eCAN RX and TX pins for CAN operation using eCAN regs*/
/* Initialize all bits of 'Master Control Field' to zero */
// Some bits of MSGCTRL register come up in an unknown state. For proper operation,
// all bits (including reserved bits) of MSGCTRL must be initialized to zero
// TAn, RMPn, GIFn bits are all zero upon reset and are cleared again
// as a matter of precaution.
ECanbRegs.CANTA.all = 0xFFFFFFFF; /* Clear all TAn bits */
ECanbRegs.CANRMP.all = 0xFFFFFFFF; /* Clear all RMPn bits */
ECanbRegs.CANGIF0.all = 0xFFFFFFFF; /* Clear all interrupt flag bits */
ECanbRegs.CANGIF1.all = 0xFFFFFFFF;
do
{
ECanbShadow.CANES.all = ECanbRegs.CANES.all;
} while(ECanbShadow.CANES.bit.CCE != 1 ); // Wait for CCE bit to be cleared..
ECanbShadow.CANBTC.all = 0;
#if (CPU_FRQ_150MHZ) // CPU_FRQ_150MHz is defined in DSP2833x_Examples.h
/* The following block for all 150 MHz SYSCLKOUT (75 MHz CAN clock) - default. Bit rate = 1 Mbps
See Note at end of file */
ECanbShadow.CANBTC.bit.BRPREG = 39;
ECanbShadow.CANBTC.bit.TSEG2REG = 2;
ECanbShadow.CANBTC.bit.TSEG1REG = 10;
#endif
#if (CPU_FRQ_100MHZ) // CPU_FRQ_100MHz is defined in DSP2833x_Examples.h
/* The following block is only for 100 MHz SYSCLKOUT (50 MHz CAN clock). Bit rate = 1 Mbps
See Note at end of file */
ECanbShadow.CANBTC.bit.BRPREG = 4;
ECanbShadow.CANBTC.bit.TSEG2REG = 1;
ECanbShadow.CANBTC.bit.TSEG1REG = 6;
#endif
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