Question

How many references to memory are needed for each type of instruction to bring an operand into a processor register

Answer 1

A computer uses a memory unit with 256K words of 32 bits each. A binary instruction code is stored in one word of memory. The instruction has four parts: an indirect bit, an operation code, a register code part to specify one of 64 registers, and an address part.

Answer 2

References to memory are needed for each type of instruction to bring an operand into a processor register are 256k words of 32 bits each.

• A binary instruction code is stored in word of memory.
• The instruction has four parts: indirect bit, an operation code, a register code part to specify one for 64 registers, an address part.
• A direct address instruction needs two references to memory: (1) Read instruction, (2) Read Operand.
• An indirect address instruction needs three references to memory: (1) Read instruction, (2) Read effective address, (3) Read operand.