Question

Function of IE1 in TCON register?

(a) External interrupt 1 Edge flag. Not related to timer operations

(b) External interrupt 1 Edge flag. Not related to timer operations

(c) External interrupt 0 single type control bit

(d) External interrupt 1 to be triggered by a falling edge signal

This question was posed to me by my school teacher while I was bunking the class.

Question is from Microcontroller (8051- Pin, Registers, Timers) in section Prototyping Embedded Devices of IOT

Answer 1

Right option is (a) External interrupt 1 Edge flag. Not related to timer operations

To elaborate: TCON register has 8 bits. 3rd bit has an IE1 register. This is an external interrupt.