Question

The state of signals in idle mode is

(a) ALE is high

(b) PSEN is high

(c) PSEN(active low) is high

(d) ALE and PSEN(active low) are high

The question was posed to me in an interview for internship.

Enquiry is from Power Control Register topic in section Microcontroller 8051 of Microprocessor

Answer 1

Correct answer is (d) ALE and PSEN(active low) are high

The explanation: ALE and PSEN(active low) remain high in Idle mode.