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

By | October 14, 2014

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 0 0 0 1 0 F=x+y R ß R1 + R2 Addition

 0 0 0 1 1 1 0 0 0 1 1 1 1 1 1 0 1 0 0 1 1 0 1 0

 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 0 1 1 0 – F=x+y R ß R1 + R2 Exclusive OR

 0 0 0 1 1 1 0 0 0 1 1 1 1 1 1 0 0 1 1 0 0 0 1 0

 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 1 0 – – – F=Shl(x) R ß Shl(R2) Shift left

 0 1 1 1 1 1 1 0 1 1 1 1 1 1 0 0

 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 0 0 – – – F=x-1 R ß R1 – 1 Decrement

 0 0 0 1 1 1 0 0 0 0 0 1 1 0 1 1

 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