machine instructions

Question

In a 16-bit computer instruction format, the size of the address field is 5 bits. The computer uses an expanding opcode technique. It has two 2-address instructions and 1024 one-address instructions. How many zero-address instructions can be formulated?

Comments

What's the change in your's and my equation ?

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they are same,

you have done calculation mistake.

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Yes calculation mistake. :( I got it now!

Answer 1

The answer given is 30720.

Answer 2

opcode(6bit)

address(5)

address(5)

#f opcodes = 2^6 =64

#f two address instruction in use =2

free opcodes =64-2=62

62*2^5 =1984 one address instruction can be formed

#f one address inst in use = 1024

free one address inst are = 1984-1024 =960

960*2^32 =30720 zero instructions can be formed

Comments

960 * 2³² is too big number ! not 30720