What will be the values of select inputs, carry-in input and result of operation if the following micro-operations are performed? – IGNOU MCA Assignment 2014 – 15

MASTER OF COMPUTER APPLICATIONS
Course Code : MCS-012
Course Title : Computer Organisation and Assembly Language Programming
Assignment Number : MCA (2)/012/Assign /2014-15
Maximum Marks : 100
Weightage : 25%

Assume that you have a machine as shown in section 3.2.2 of Block 3 having the micro-operations as given in Figure 10 on page 62 of Block 3. Consider that R1 and R2 both are 8 bit registers and contains 0001 1100 and 0111 1110 respectively. What will be the values of select inputs, carry-in input and result of operation (including carry out bit) if the following micro-operations are performed? (For each micro-operation you may assume the initial value of R1 and R2 as given above).

(i) Addition of R1 and R2

(ii) Exclusive OR of R1 and R2

(iii)Shift left R2 once

(iv) Decrement R1

(i) Addition of R1 and R2

 

 

 

 

S3	S2	S1	S0	Ci	F	Micro-operation	Name	Value of Result R
0	0	0	1	0	F=x+y	R ß R1 + R2	Addition	1001 1010

  

 (ii) Exclusive OR of R1 and R2

 

 

 

S3	S2	S1	S0	Ci	F	Micro-operation	Name	Value of Result R
0	1	1	0	–	F=x+y	R ß R1 + R2	Exclusive OR	0110 0010

 

 (iii)Shift left R2 once

 

 

 

S3	S2	S1	S0	Ci	F	Micro-operation	Name	Value of Result R
1	0	–	–	–	F=Shl(x)	R ß Shl(R2)	Shift left	1111 1100

(iv) Decrement R1

 

 

 

S3	S2	S1	S0	Ci	F	Micro-operation	Name	Value of Result R
0	0	–	–	–	F=x-1	R ß R1 – 1	Decrement	0001 1011