Getting interrupts to work on Zynq 7000 (ARM Cortext-A9) in Vitis

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1

I’ve never used a RTOS before and I’m trying to get interrupts working on a Xilinx Zynq 7000 FPGA with an ARM Cortex-A9 PS in Vitis 2022.1.

I have a 1 HZ clock tied to interrupt 15 on the PS which should be ID 91.

Here’s the code I found and tried, but doesn’t work:

extern XScuGic xInterruptController;

Xil_ExceptionRegisterHandler(XIL_EXCEPTION_ID_INT,
	(Xil_ExceptionHandler) XScuGic_InterruptHandler, &xInterruptController);

XScuGic_SetPriorityTriggerType(&xInterruptController, XPS_FPGA15_INT_ID, 4, 3);

XScuGic_Connect(&xInterruptController, XPS_FPGA15_INT_ID,
	(Xil_ExceptionHandler)ExtIrq_Handler, (void *)NULL);

XScuGic_Enable(&xInterruptController, XPS_FPGA15_INT_ID);

Could someone please help? Am I missing some code or using it wrong?

THANKS!

2

Still no luck.

I found some more example code which is slightly different than my first post, but still doesn’t work:

extern XScuGic xInterruptController;  // defined in portZynq7000.c
static XScuGic_Config *GicConfig;

void ExtIrq_Handler(void *InstancePtr)
{
	printf("ExtIrq_Handler\n\r");
}


int interrupt_init()
{
	int Status;

	GicConfig = XScuGic_LookupConfig(XPAR_SCUGIC_0_DEVICE_ID);
	if (NULL == GicConfig) {
		return XST_FAILURE;
	}

	Status = XScuGic_CfgInitialize(&xInterruptController, GicConfig, GicConfig->CpuBaseAddress);
	if (Status != XST_SUCCESS) {
		return XST_FAILURE;
	}

	Xil_ExceptionRegisterHandler(XIL_EXCEPTION_ID_INT,
			(Xil_ExceptionHandler) XScuGic_InterruptHandler, &xInterruptController);

	XScuGic_SetPriorityTriggerType(&xInterruptController, XPS_FPGA15_INT_ID, 4, 3);

	XScuGic_Connect(&xInterruptController, XPS_FPGA15_INT_ID,
			(Xil_ExceptionHandler)ExtIrq_Handler, (void *)NULL);

	XScuGic_Enable(&xInterruptController, XPS_FPGA15_INT_ID);

	return XST_SUCCESS;
}

XPAR_SCUGIC_0_DEVICE_ID = 0
XIL_EXCEPTION_ID_INT = 5
XPS_FPGA15_INT_ID = 91

Can anyone help?

3

Does the interrupt work in a bare metal application - without FreeRTOS or any other OS? If so, are you configuring the interrupt after starting the scheduler, so after the scheduler configures the interrupt controller?

4

I’ve been unsuccessful in getting this to work in bare metal code as well.

The interrupt to the PS is connected to a 1 Hz clock, so there is nothing to configure. Am I correct?

5

I don’t know the specifics of the clock or peripheral - but recommend getting the interrupt working in bare metal first, then FreeRTOS second. It only becomes a FreeRTOS usage question for this forum if it works in the non-RTOS configuration, but not the RTOS configuration.

6

I have it working. I need to add: Xil_ExceptionEnable();

7

Thank you for reporting back.