Question

A hypothetical processor supports 2-address instructions and 1-address instructions. It has 32-bit instruction and 12-bit addresses. If there are 254 2-address instructions then minimum and maximum number of 1-address instructions can be formulated respectively are

• A. 1,8192
• B. 1, 1 M
• C. 0, 8192
• D. 0,1M

Answer 1

The correct option is A 1,8192



$\text{max.opcode}=2^8=256\underset{–}{\text{used opcode}=254}\underset{–}{\text{unused opcode}=2}$




$\text{max.opcode}=2\ast 2^{12}=2^{13}=8192$

min. opcode = 1 (Atleast 1 instruction should be present to be supported)