MPC5604S priority issue

[akhilprasad]

I am using MPC5604S and eclipse based code warrior. I have enabled ADC and System timer using interrupt. ADC should have lowest priority and system timer should have highest priority.

Can anyone share me the code for the same. I need MPC5604S code only because am facing issue in priority. ADC interrupt gets called frequently than system timer interrupt. kindly guide me. 

[davidtosenovjan]

CW has pre-prepared everything what is needed to handle interrupts and exceptions.
Generated stationery contains files Exceptions.c and IntcInterrupts.c.

These files includes required initialization and also function INTC_InstallINTCInterruptHandler that is intended to create interrupt vector table and has 3 parameters (name of the function, vector and priority).

You can add function like this to your project:
static void Interrupts_init(void)
{
    // Initialize interrupts and exceptions
    EXCEP_InitExceptionHandlers();
    INTC_InitINTCInterrupts();
    
    // Create interrupt vector table
    INTC_InstallINTCInterruptHandler(handler_1,103,2);
    NTC_InstallINTCInterruptHandler(handler_2,102,1);      
    
    /* Lower INTC's current priority */
    INTC.CPR.B.PRI = 0;       
}

Also pay attention to interrupt nesting:
If INTC_NESTED_INTERRUPT == 0
 then interrupt handler is called directly, interrupts are disabled during ISR execution and ISR cannot be affected by interrupt with higher priority

If INTC_NESTED_INTERRUPT == 1
 then interrupt handler contains necessary prolog and epilog and interrupts are enabled during prolog allowing interrupt with higher priority to be handled first

Good luck and have a nice day.

[akhilprasad]

thanks for the input. but i can explain u what is the issue am facing. I have 3 interrupts

a. ADC   -   low priority

b. System Timer   - highest Priority

c. 2 CAN RX interrupts.   - medium priority

So during ADC initialization am using this below code

       INTC_InstallINTCInterruptHandler(ADC0_EOC_isr,62,2);
       INTC.CPR.R = 2;.

- During System Timer initialization am using this below code

      INTC_InstallINTCInterruptHandler(STM0_interrupt_isr,30,15);
      INTC.CPR.R = 15;

- During CAN initialization am using this below code

       INTC_InstallINTCInterruptHandler(FCAN0_ReceiveInt_isr,72,9);

       INTC.CPR.R = 15;

       INTC_InstallINTCInterruptHandler(FCAN1_ReceiveInt_isr,92,10);

       INTC.CPR.R = 15;

Now the issue is the interrupts are not working based on priority. ADC interrupt is continuously invoked and not allowing it to go to other interrupts.

So I gave INTC.CPR.R in all the initialization because from the datasheet am not clear how to use it. so can u explain me what is the relation between  INTC.CPR.R and INTC.PSR[vectorNum].B.PRI register. It will be great if u share me a sample code with all these functionalities I mentioned above. 

Thanks in advance. :smileyhappy:

[davidtosenovjan]

Have you tried it this way?

INTC_InstallINTCInterruptHandler(ADC0_EOC_isr,62,2);
INTC_InstallINTCInterruptHandler(STM0_interrupt_isr,30,15);
INTC_InstallINTCInterruptHandler(FCAN0_ReceiveInt_isr,72,9);
INTC_InstallINTCInterruptHandler(FCAN1_ReceiveInt_isr,92,10);
INTC.CPR.R = 0;

The INTC_CPR masks any peripheral or software settable interrupt request set at the same or lower
priority as the current value of the INTC_CPR[PRI] field from generating an interrupt request to the
processor.

[akhilprasad]

Actually the issues was with the CAN interrupt configuration. After re-configuring the interrupt it was working fine.

Thanks for the support :smileyhappy:.