[Zybo Z7 clocks and xscutimer]

Do you discover how Time load value works?? I'm trying to generate a 20 ms interrupt with a Zybo Z7 and I don't know what value I have to choose. Could you help me??

Thanks :)

[Timer interrupt Zybo Z7 Timer Load Value]

I'm working in a project with a Zybo Z7-10 and I want to generate a timer interrupt every 20 ms. I did a vivado and vitis project but I don't know what is the correct Timer Load Value to generate this interrupt. Could someone help me? 

Thanks a lot.

PD: This is the project.

#include <stdio.h>
#include "xparameters.h"
#include "xil_printf.h"
#include "xgpio.h"
#include "xil_types.h"
#include "sleep.h"
#include "xtmrctr.h"
#include "xscugic.h"
#include "xil_exception.h"

// Get device IDs from xparameters.h
#define BTN_ID XPAR_AXI_GPIO_BUTTONS_DEVICE_ID
#define LED_ID XPAR_AXI_GPIO_LEDS_DEVICE_ID
#define LED_RGB_ID XPAR_AXI_GPIO_RGB_LED_DEVICE_ID
#define SW_ID XPAR_AXI_GPIO_SWITHCES_DEVICE_ID

#define INTC_DEVICE_ID XPAR_PS7_SCUGIC_0_DEVICE_ID
#define TMR_DEVICE_ID XPAR_TMRCTR_0_DEVICE_ID
#define INTC_TMR_INTERRUPT_ID XPAR_FABRIC_AXI_TIMER_0_INTERRUPT_INTR

#define TMR_LOAD    0x00659F9F

#define BTN_CHANNEL 1
#define LED_CHANNEL 1
#define SW_CHANNEL 1
#define LED_RGB_CHANNEL 1

#define BTN_MASK 0b1111
#define LED_MASK 0b0000
#define SW_MASK 0b1111
#define LED_RGB_MASK 0b0000

XScuGic INTCInst;
XTmrCtr TMRInst;

static void TMR_Intr_Handler(void *baseaddr_p);
static int IntcInitFunction(u16 DeviceId, XTmrCtr *TmrInstancePtr);

void TMR_Intr_Handler(void *data){
    if(XTmrCtr_IsExpired(&TMRInst, 0)){
        if(tmr_count == 10){
            XTmrCtr_Stop(&TMRInst,0);
            xil_printf("Interrupcion\r\n");
            XTmrCtr_Reset(&TMRInst,0);
            XTmrCtr_Start(&TMRInst,0);
    }
}

int InterruptSystemSetup(XScuGic *XScuGicInstancePtr){

    Xil_ExceptionRegisterHandler(XIL_EXCEPTION_ID_INT,
            (Xil_ExceptionHandler) XScuGic_InterruptHandler,
            XScuGicInstancePtr);

    Xil_ExceptionEnable();

    return XST_SUCCESS;
}

int IntcInitFunction(u16 DeviceId, XTmrCtr *TmrInstancePtr){
    XScuGic_Config *IntcConfig;
    int status;

    IntcConfig = XScuGic_LookupConfig(DeviceId);
    status = XScuGic_CfgInitialize(&INTCInst, IntcConfig,
            IntcConfig->CpuBaseAddress);
    if(status != XST_SUCCESS)
        return XST_FAILURE;

    status = InterruptSystemSetup(&INTCInst);
    if(status != XST_SUCCESS)
        return XST_FAILURE;

    status = XScuGic_Connect(&INTCInst, INTC_TMR_INTERRUPT_ID,
            (Xil_ExceptionHandler) TMR_Intr_Handler, (void *) TmrInstancePtr);
    if(status != XST_SUCCESS)
        return XST_FAILURE;

    XScuGic_Enable(&INTCInst, INTC_TMR_INTERRUPT_ID);

    return XST_SUCCESS;
}

int main() {

    XGpio_Config *cfg_ptr;
    XGpio led_device, btn_device, sw_device, led_rgb_device;
    u32 data, data1;
    int status;

    xil_printf("Entered function main\r\n");

    // Initialize LED Device
    cfg_ptr = XGpio_LookupConfig(LED_ID);
    XGpio_CfgInitialize(&led_device, cfg_ptr, cfg_ptr->BaseAddress);

    // Initialize Button Device
    cfg_ptr = XGpio_LookupConfig(BTN_ID);
    XGpio_CfgInitialize(&btn_device, cfg_ptr, cfg_ptr->BaseAddress);

    // Initialize Switch Device
    cfg_ptr = XGpio_LookupConfig(SW_ID);
    XGpio_CfgInitialize(&sw_device, cfg_ptr, cfg_ptr->BaseAddress);

    // Initialize LED RGB Device
    cfg_ptr = XGpio_LookupConfig(LED_RGB_ID);
    XGpio_CfgInitialize(&led_rgb_device, cfg_ptr, cfg_ptr->BaseAddress);

    // Set Button Tristate
    XGpio_SetDataDirection(&btn_device, BTN_CHANNEL, BTN_MASK);

    // Set Led Tristate
    XGpio_SetDataDirection(&led_device, LED_CHANNEL, LED_MASK);

    // Set Button Tristate
    XGpio_SetDataDirection(&sw_device, BTN_CHANNEL, SW_MASK);

    // Set Led Tristate
    XGpio_SetDataDirection(&led_rgb_device, LED_RGB_CHANNEL, LED_RGB_MASK);

    status = IntcInitFunction(INTC_DEVICE_ID, &TMRInst);
    if(status != XST_SUCCESS)
        return XST_FAILURE;

    //Setup the timer
    status = XTmrCtr_Initialize(&TMRInst, TMR_DEVICE_ID);
    if(status != XST_SUCCESS)
        return XST_FAILURE;

    XTmrCtr_SetHandler(&TMRInst, (XTmrCtr_Handler) TMR_Intr_Handler, &TMRInst);
    XTmrCtr_SetResetValue(&TMRInst, 0, TMR_LOAD);
    XTmrCtr_SetOptions(&TMRInst, 0, XTC_INT_MODE_OPTION | XTC_AUTO_RELOAD_OPTION);

    XTmrCtr_Start(&TMRInst,0);
    xil_printf("Empieza");

    while (1) {
        data = XGpio_DiscreteRead(&btn_device, BTN_CHANNEL);
        XGpio_DiscreteWrite(&led_device, LED_CHANNEL, data);
        data1 = XGpio_DiscreteRead(&sw_device, BTN_CHANNEL);
        XGpio_DiscreteWrite(&led_rgb_device, LED_RGB_CHANNEL, data1);
        usleep(100000);
    }
}