October 6, 2023
October 6, 2023
October 6, 2023
###### Software-design
October 6, 2023
 Question 667
Consider a control unit generating the control signals. These control signals are divided into five mutually exclusive groups as shown below:

How many bits are saved using the Vertical Microprogrammed instead of Horizontal Microprogrammed control unit?
 A 14 B 34 C 20 D None
Question 667 Explanation:
In horizontal microprogramming we need 1 bit for every control word, therefore total bits in horizontal microprogramming
= 3 + 7 + 10 + 12 + 2
= 34
Now lets consider vertical microprogramming. In vertical microprogramming no. of bits required to activate 1 signal in group of N signals, is ⌈log2 N⌉. And in the question 5 groups contains mutually exclusive signals,
group 1 = ⌈log2 3⌉ = 2
group 2 = ⌈log2 7⌉ = 3
group 3 = ⌈log2 10⌉ = 4
group 4 = ⌈log2 12⌉ = 4
group 5 = ⌈log2 2⌉ = 1
Total bits required in vertical microprogramming
= 2+ 3 + 4 + 4+ 1
= 14
So, number of bits saved is
= 34 – 14
= 20
Question 667 Explanation:
In horizontal microprogramming we need 1 bit for every control word, therefore total bits in horizontal microprogramming
= 3 + 7 + 10 + 12 + 2
= 34
Now lets consider vertical microprogramming. In vertical microprogramming no. of bits required to activate 1 signal in group of N signals, is ⌈log2 N⌉. And in the question 5 groups contains mutually exclusive signals,
group 1 = ⌈log2 3⌉ = 2
group 2 = ⌈log2 7⌉ = 3
group 3 = ⌈log2 10⌉ = 4
group 4 = ⌈log2 12⌉ = 4
group 5 = ⌈log2 2⌉ = 1
Total bits required in vertical microprogramming
= 2+ 3 + 4 + 4+ 1
= 14
So, number of bits saved is
= 34 – 14
= 20