Question

Which of the following is also known as tri-state?

(a) output port

(b) input port

(c) parallel port

(d) output-input port

The question was asked by my college professor while I was bunking the class.

Question is taken from Parallel Ports topic in section Basic Peripherals of Embedded Systems

Answer 1

Correct option is (a) output port

The explanation: The progression in the parallel ports provides a third register or an individual control bit which can make the pin in a high impedance state. An output port which can do this is also known as tri-state, that is, logic high, logic low and a high impedance state.