Computer Architecture/Organization

a. Give a formula for computing 27n, using Booth's algorithm.

b. Given the following assembly language:

clear R1 R1 0

sub R1, R2, R3 R1 R2 R3

add R1, R2, R3 R1 R2 + R3

shl R1 R1 shl R1

in R1 R1 input

out R1 output R1

for a machine with an 8-bit word, and registers R0, and R1, write a program that reads in a value, n, and outputs 27n. The program has been started in the table below. Finish the program.

c. Trace your program on input n = 3 by showing the contents of R0 and R1 after each instruction. Again, use the table below.

Instruction	R0	R1
in R1	XXXXXXXX	00000011
clear R0	00000000	00000000
sub R0, R0, R1	11111101	00000011