Applied Test Series

Question

An instruction is stored at location 300 with its address field at location 301. The address field has the value 400. A processor register R1 contains the number 200. Evaluate effective address if the addressing mode of the instruction is Index with R1 as the index register.

Comments

Indexed = 200 + 400 = 600

Index = Base address(address field value) + Index register content

Index addressing mode is a category of displacement addressing mode. In index mode, the addition of base address and displacement index value gives the actual physical address of the operand in memory.

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@LRU

Index, EA = 200 + 400 = 600…

In the Indexed Register Addressing Mode, the effective address is the sum of the contents of 2 registers.

Since, R1 here acts as the index register and the address field contains the value 400, hence Effective Address = 200 + 400 = 600...

 

1. https://gateoverflow.in/104006/co-important-question-need-answer-howw 

 

2. https://gateoverflow.in/78730/gate-application-coa-morris-mano-numerical-addressing-modes 

 

3. https://gateoverflow.in/188873/effective-address-calculation