Microblaze AXI Timer on Arty A7-35

[penguin]

Hi. I am new to Vivado platform / Digilent's Arty board. 

I am trying to get Microblaze to work with Axi timer to trigger interrupt at a certain rate. 

 

The image below shows the overall architecture.

 

The board is successfully talking via UART and I can print on Terminal.

I compiled the code below and no error came up; I ran the program but the interrupt is not triggered at all.

#include <stdio.h>
#include "platform.h"
#include "xil_printf.h"
#include "xintc.h"
#include "xtmrctr.h"		
#include "xparameters.h"
#include "xil_exception.h"
#include "xstatus.h"

XTmrCtr TimerCounterInst;
XIntc InterruptController;

#define TMRCTR_DEVICE_ID	XPAR_TMRCTR_0_DEVICE_ID
#define INTC_DEVICE_ID		XPAR_INTC_0_DEVICE_ID
#define TMRCTR_INTERRUPT_ID	XPAR_INTC_0_TMRCTR_0_VEC_ID
#define TIMER_CNTR_0		0
#define RESET_VALUE		500000

void TimerCounterHandler(void *CallBackRef, u8 TmrCtrNumber);
//static int count = 0;
volatile int TimerExpired;

int main()
{
	/* Initialization */
	XStatus  status;
	// 1. Platform
  	init_platform();
	print("Platform initialized \r\n");
  
	// 2. Timer Counter
	status = XTmrCtr_Initialize(&TimerCounterInst, TMRCTR_DEVICE_ID);
	if (status != XST_SUCCESS){
		print("Timer counter initialization failed \r\n");
		return status;
	}
	print("Timer counter initialized \r\n");


	// 3. Interrupt
  	status = XIntc_Initialize(&InterruptController, INTC_DEVICE_ID);
	print("Interrupt initialized \r\n");

	status = XIntc_Connect(&InterruptController, TMRCTR_INTERRUPT_ID,
							(XInterruptHandler)XTmrCtr_InterruptHandler,
							(void *)&TimerCounterInst);
	if (status != XST_SUCCESS){
		print("Interrupt connect failed \r\n");
		return status;
	}
	print("Interrupt set up \r\n");

	// 4. Interrupt Start
	status = XIntc_Start(&InterruptController, XIN_REAL_MODE);
	if (status != XST_SUCCESS){
		print("Interrupt start failed \r\n");
		return status;
	}
	XIntc_Enable(&InterruptController, TMRCTR_INTERRUPT_ID);
	Xil_ExceptionInit();
	Xil_ExceptionRegisterHandler(XIL_EXCEPTION_ID_INT,
			 (Xil_ExceptionHandler)XIntc_InterruptHandler,
			 &InterruptController);
	Xil_ExceptionEnable();

	// 6. Timer Counter Handler
	XTmrCtr_SetHandler(&TimerCounterInst, TimerCounterHandler,
					   &TimerCounterInst);
	print("Timer counter handler set \r\n");

	// 7. Timer Options
	XTmrCtr_SetOptions(&TimerCounterInst, TIMER_CNTR_0,
					   XTC_INT_MODE_OPTION | XTC_AUTO_RELOAD_OPTION);
	print("Timer options set \r\n");
	XTmrCtr_SetResetValue(&TimerCounterInst, TIMER_CNTR_0, RESET_VALUE);
	print("Timer reset value set \r\n");

	// 8. Timer Start
	XTmrCtr_Start(&TimerCounterInst, TIMER_CNTR_0);
	print("Timer start \r\n");

	print("ALL PASS \r\n");
	while(1){
		//DO NOTHING FOR NOW
	}

    cleanup_platform();
    return 0;
}

void TimerCounterHandler(void *CallBackRef, u8 TmrCtrNumber){
	XTmrCtr *InstancePtr = (XTmrCtr *)CallBackRef;
	print("IN TIMER\r\n");
	if (XTmrCtr_IsExpired(InstancePtr, TmrCtrNumber)){
		print("Expired\r\n");
	}
}

 

But when I ran the self test after initialization of XTmrCtr, it actually does not pass the test with a status of 1 (which is indicated as failure in xstatus.h as #define XST_FAILURE   1L)

	status = XTmrCtr_SelfTest(&TimerCounterInst, TMRCTR_DEVICE_ID);
		if (status != XST_SUCCESS) {
			xil_printf("Timer self-test failed: %d \r\n", status);
			return XST_FAILURE;
		}
	print("Timer self-test pass \r\n");

 

If I understand correctly, the self-test is to check if the hardware is set up correctly.

I don't know where in the block design side is wrong. I am using following setup:

1. Clock wizard with 166.667 MHz and 200MHz

2. DDR3 SDRAM that takes in 166.667MHz as sys_clk and 200MHz as ref_clk

3. Microblaze with a separate clock [mig_7series/ui_clk (83MHz)]

4. UARTlite (interrupt connected to axi_intc via microblaze_0_xlconcat)

5. Axi Timer  (interrupt connected to axi_intc via microblaze_0_xlconcat)

 

I would appreciate your help!

Please let me know if you need any other information.

 

Thanks!

[jpeyron]

Hi @penguin,

Here is a Nexys Video and here is a Cmod A7 forum thread that has a verified uart interrupt project that should be helpful getting your uart interrupt working

best regards,

Jon

[D@n]

166.667MHz out of the clocking wizard and going into the DDR3 MIG controller?  That sounds too high by a factor of two

Dan

[jpeyron]

Hi @penguin and @D@n,

We used a 166.667 MHz and a 200 MHz clock with the MIG as shown in this getting started with microblaze tutorial.

best regards,

Jon

[penguin]

@jpeyron

Thank you for your response.

I apologize if I didn't make it clear.

I was looking to get timer interrupt to work not the UART interrupt.

 

I have found that self-test did not pass for the timer, which suggests that the hardware did not set up properly but I can't find where the problem is.

I followed the tutorial and just added AXI timer to the overall architecture. 

 

Thanks

[jpeyron]

Hi @penguin,

Have you had a chance to look through the AXI Timer v2.0 LogiCORE IP Product Guide.

What mode are you trying to use?

The getting started with microblaze servers tutorial uses the AXI Timer with the Arty-A7.

best regards,

Jon

[penguin]

@jpeyron

I really appreciate your reply.

I actually followed the tutorial you mentioned from the beginning like you said, it uses AXI Timer.

 

I am using XTC_INT_MODE_OPTION and XTC_AUTO_RELOAD_OPTION which allows compare-mode with interrupt.

Thanks,

Penguin