Using a prescalar of 64, write a program to generate a delay of 1920us. Assume XTAL = 8MHz.

Sure, here is a simple program in C for AVR microcontrollers that generates a delay of 1920us using a prescalar of 64. We assume that the crystal oscillator (XTAL) frequency is 8MHz.

#include <avr/io.h>
#include <avr/interrupt.h>

#define PRESCALER 64
#define XTAL 8000000
#define DELAY_US 1920

int main(void)
{
    // Calculate the timer count
    uint16_t timerCount = (XTAL / PRESCALER / 1000000 * DELAY_US) - 1;

    // Set the timer count
    OCR1A = timerCount;

    // Set the timer prescaler
    TCCR1B |= (1 << CS10) | (1 << CS11);

    // Enable timer compare interrupt
    TIMSK1 |= (1 << OCIE1A);

    // Enable global interrupts
    sei();

    while (1)
    {
        // Do nothing, wait for interrupt
    }

    return 0;
}

ISR(TIMER1_COMPA_vect)
{
    // Toggle an output pin or do something else to mark the delay
}

This program sets up Timer1 to generate a compare match interrupt every 1920us. The interrupt service routine (ISR) for the compare match interrupt can be used to do something every 1920us, like toggling an output pin. The timer count and prescaler are calculated based on the desired delay and the XTAL frequency.