CCS/TMS320F28335: DSP28335 can't enter CAN interrupt after running for a long time.

Please check the PIE register values and also core register IER and INTM bit. There are multiple bits that need to be at the correct value from the CAN module to the PIE to the core.

Thanks, I have read these values. They have no problem. The problem I have now is that after the program runs for 354 minutes, when the CAN enters the receive interrupt, after the mailbox 31 receives the data, the remaining mailboxes will not receive data. At this time, RMP and RML are both set. CAN cannot run to ECanaRegs.CANRMP.all = 0xFFFF0000, so RMP and RML cannot be cleared; my program is mainly used to generate PWM wave, switching frequency is 15K.

interrupt void CAN0A_intISR(void)
{
volatile Uint16 TempPIEIER;
Uint16 i;
TempPIEIER = PieCtrlRegs.PIEIER9.all; // Save PIEIER register for later
IER |= M_INT9; // Set global priority by adjusting IER
IER &= 0x0104;
PieCtrlRegs.PIEIER3.all &= 0x0001; // Set group priority by adjusting PIEIER2 to allow INT2.2 to interrupt current ISR
PieCtrlRegs.PIEACK.all = 0xFFFF; // Enable PIE interrupts
asm(" NOP"); // Wait one cycle
EINT;
if(ECanaRegs.CANGIF0.bit.MIV0 == 16)
{
for(CAN_read=0;CAN_read<=15;CAN_read++)
{
mailbox_read(CAN_read+16); // This func reads the indicated mailbox data
CAN_Recei[CAN_read][0]=TestMbox1;
CAN_Recei[CAN_read][1]=TestMbox2;
}
gCAN_recei_CAN();
bzw = 1;
bzw_CANjiance =0;
zdjs++;
zdjs1++;
if(zdjs == 1)
{
P_CheckSet();
P_GetSetFromRam();
}
if(zdjs >=2)
{
zdjs =2;
}
}
ECanaRegs.CANRMP.all = 0xFFFF0000;
PieCtrlRegs.PIEACK.bit.ACK9 = 1;
EINT;
for(i = 1; i <= 10; i++) {}
DINT;
PieCtrlRegs.PIEIER9.all = TempPIEIER;
}

Today I increased the CAN baud rate to 500K, which was originally 100K. When the program runs for 71 minutes, CAN does not enter the receive interrupt. The baud rate increased by 5 times, and the running time for CAN to enter the receive interrupt was reduced by one fifth. Can you tell me why? Thank you.