2,710 views
5 votes
5 votes

A hypothetical cpu supports $300$ instructions.each instruction takes $5$ cycle to accomplish the execution. the control unit is designed using vertical programming which has $130$ control signals $,64$ flags and $12$ branch conditions .$X$ and $Y$ represent the number of bits required for control address register$(CAR)$ and control data register$(CDR)$ respectively.value of $X+Y$ is ______?


How to work with branch condition in micro programming :(

2 Answers

5 votes
5 votes
Total micro operation which have to be stored in control memory is = 300*5 =1500

Number of bits are required to address one of the micro operation from control memory is log(1500) = 11 bits (CAR)

Number of bits are required CMDR (Control memory data register) = Flag(6) + branch Condition(4) + Control signals(8) + next micro operation address(11) = 29 bits

therefore CAR+CDR =40 bits
0 votes
0 votes
40 bits

x=11   as 300 instructions takes 5 cycles each so total references 300*5=1500
           x=log1500=11
y=29

         y=log12+log130 (as given vertical)+log64+log1500

Related questions