Question

A digital computer supports 2-address and 1-address instructions. The size of instruction is 16-bits and address size is 6-bits. If these are 12 2-address instructions then minimum and maximum number of 1-address instructions supported are respectively?

Answer 1

$16-(6+6)=4-bits$

$\text{Max opcode}=2^4=16\underset{–}{Usedopcode=12}\text{Unused opcode}=4$



Max opcode $=4\ast 2^6=256$

Max 1-address intructions = 256

Min 1-address instructions = 1 [min 1 required to be supported]