The Gateway to Computer Science Excellence
First time here? Checkout the FAQ!
x
+2 votes
225 views
A computer supports one address and two address instructions. All the Addresses are the memory addresses. Memory size is 1Mbyte. How many one address instructions are possible if it has 240 two addresses instructions? (Assume binary instructions code has 48 bits)
in CO and Architecture by (37 points) | 225 views

1 Answer

+1 vote
Best answer

 in this problem  total size of instruction code = 48 bit

  memory address = 20 bit

  in two address mode =    tag + address1 + address2

                                    =  8  + 20 + 20

       given that  240  is two address instruction

remaining  =  2^8 -  240

                 =  256 - 240 = 16

 hence  one address instruction  =  16* 220   =  224   

by Loyal (6.2k points)
selected by
0
what is the meaning of tag and how is it 8?
+1
because total instruction 48 bit  if u substract 2 address it means (48-20-20) = 8 bit
+1

@ritus

sub a,b ----> in this instruction a and b are memory addresses and sub is opcode ( tag in this solution )

0
ok thank u sir.
0
sir but how did we get memory address=20?
+1

@ritus

Memory Size = 1 MB = 220 B ===> 20 bits required to identify one Byte in this architecture

Related questions

+2 votes
2 answers
2
0 votes
0 answers
7
asked Oct 24, 2018 in CO and Architecture by Balaji Jegan Active (4.9k points) | 20 views
Quick search syntax
tags tag:apple
author user:martin
title title:apple
content content:apple
exclude -tag:apple
force match +apple
views views:100
score score:10
answers answers:2
is accepted isaccepted:true
is closed isclosed:true
50,309 questions
55,743 answers
192,231 comments
90,499 users