Question

Identify the row and the column for the following case when for the row D3-D0= 1110 and for the column D3-D0= 1101

(a) first row and second column

(b) first row and third column

(c) second row and first column

(d) second row and second column

This question was posed to me by my college professor while I was bunking the class.

Asked question is from Keyboard Interfacing in division AVR Microcontroller of Microcontroller

Answer 1

Correct answer is (a) first row and second column

For explanation I would say: To identify the key that is pressed from this particular combination, we obtain that the key belongs to the first row and the second column as the D0 bit of the row port and the D1 bit of the column port are zero.