A certain microprocessor requires 4.5 microseconds to respond to an interrupt. Assuming that the three interrupts I1, I2 and I3 require the following execution time after the interrupt is recognized: 25, 35, 20us. I1 has highest priority, I3 lowest. What is the possible range of time for I3 to be executed?
- A. 24.5 microseconds to 39.5 microseconds
- B. 24.5 microseconds to 93.5 microseconds
- C. 4.5 microseconds to 24.5 microseconds
- D. 29.5 microseconds 93.5 microseconds
Answer: B. 24.5 microseconds to 93.5 microseconds
Explanation: Min time (no other interrupts): 4.5 (response) + 20 (exec) = 24.5. Max time (I1 and I2 occur): 4.5 + 25 (I1) + 4.5 + 35 (I2) + 4.5 + 20 (I3) = 93.5.