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GATE 2015 CS – Question 22

Computer Organization and Architecture · Instruction Set and Addressing Modes · 1 mark · Multiple choice

For computers based on three-address instruction formats, each address field can be used to specify which of the following:

(S1) A memory operand

(S2) A processor register

(S3) An implied accumulator register

  1. Either S1 or S2
  2. Either S2 or S3
  3. Only S2 and S3
  4. All of S1, S2 and S3

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Show answer and explanation

Correct answer: (A) Either S1 or S2

Explanation

In a three-address format each address field names an operand explicitly, either a memory location or a register. An implied accumulator is not named in any address field, so S3 does not apply. Each field is therefore either S1 or S2.