Given below are two statements : One is labelled as Assertion A and the other is labelled as Reason R : Assertion (A) : The biggest advantage of using a PROM as a programmable logic device is that its design can be changed and modified rapidly...

89) Given below are two statements : One is labelled as Assertion A and the other is labelled as Reason R :

Assertion (A) : The biggest advantage of using a PROM as a programmable logic device is that its design can be changed and modified rapidly.

Reason (R) : The PROM can generate any possible logic function of input variables because it generates every possible AND product term.

In the light of the above statements, choose the correct answer from the options given below :

(1) Both (A) and (R) are true and (R) is the correct explanation of (A)

(2) Both (A) and (R) are true but (R) is not the correct explanation of (A)

(3) (A) is true but (R) is false

(4) (A) is not true but (R) is true

Answer: D

Solution

Assertion (A): False. Standard PROMs are "One-Time Programmable" (OTP). Once programmed, the fuses are blown and the design cannot be changed or modified. Reprogrammability is a feature of EPROMs, EEPROMs, or Flash memory, but not basic PROMs.
Reason (R): True. A PROM architecture consists of a fixed "AND" array (which decodes inputs into all possible minterms) and a programmable "OR" array. This allows it to implement any Boolean function of its input variables.

Since Assertion (A) is false (not true) and Reason (R) is true, the correct answer is (4).