A control unit which support 128K control word memory. Processor hardware support 60 control signal and 8 flags. What is the size of horizontal control word.
(A) 26 bits
(B) 80 bits
(C) 24 bits
(D) 84 bits


Answer: (B)

Explanation: Computer supported control word format:

Branch condition = 0,
3 bits for 8 flag,
60 control signal and it is given that horizontal control word is supported. So, 60 bits will be there for control signals.
17 bits for 128K word memory.

Therefore, size of horizontal control word
= 0 + 3 + 60 + 17
= 80 bits

So, option (B) is correct.

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