(a) Consider the following structure of the instruction register.
What is the maximum number of distinct operation codes that
can be recognized and executed by the processor on this machine?
What is the maximum memory size on this machine?
┌─────┬──────┬──────┐
│ Op code │ Address-1 │ Address-2 │
└─────┴──────┴──────┘
8 bits 20 bits 20 bits
(b) Suppose a machine has 4MB of memory. However, the MAR (Memory Address
Register) contains only 20 bits. Explain how it might be possible to
address all 4MB memory cells using a MAR that contains only 20 bits.
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