Question

A 24 MHz microcontroller executes one instruction per clock cycle. If an interrupt service routine consumes 120 cycles, then the time taken by the ISR to execute is:

• A. \(10\ \mu\text{s}\)
• B. \(5\ \mu\text{s}\)
• C. \(20\ \mu\text{s}\)
• D. \(1\ \mu\text{s}\)

Hint:

To solve execution time problems quickly, use the direct formula:
\(\text{Time} = \frac{\text{Total Cycles}}{\text{Frequency}}\). Substituting the values here yields \(\frac{120}{24 \times 10^6} = 5 \times 10^{-6}\text{ s} = 5\ \mu\text{s}\).

Answer 1

The Correct Option is B