Consider a hypothetical 64-bit microprocessor having 64-bit instructions composed of two fields. The first 4 bytes contain the opcode, and the remainder an immediate operand or an operand address.
a. What is the maximum directly addressable memory capacity?
b. What ideal size of microprocessor address buses should be used? How will system speed be affected for data buses of 64 bits, 32 bits and 16 bits?
c. How many bits should the instruction register contain if the instruction register is to contain only the opcode, and how many if the instruction register is to contain the whole instruction?