Which register stores the address of the current instruction?

memory address register
memory address register (MAR) – holds the address of the current instruction that is to be fetched from memory, or the address in memory to which data is to be transferred.

What is the purpose of the instruction register?

This register holds the current instruction so that it can be decoded and input to the control and timing unit. Specifically, the instruction register holds the opcode which defines the type of instruction.

What is stored in the program counter register?

A program counter is a register in a computer processor that contains the address (location) of the instruction being executed at the current time. As each instruction gets fetched, the program counter increases its stored value by 1. Within a computer, an address is a specific location in memory or storage.

Which register is used to hold address of next instruction after current instruction execution?

The program counter (PC), commonly called the instruction pointer (IP) in Intel x86 and Itanium microprocessors, and sometimes called the instruction address register (IAR), the instruction counter, or just part of the instruction sequencer, is a processor register that indicates where a computer is in its program …

What is the use of program counter?

The program counter, PC, is a special-purpose register that is used by the processor to hold the address of the next instruction to be executed. The PLA automatically updates the PC to point to the next instruction during the op-code decode cycle.

What is the difference between program counter and instruction register?

The program counter (PC) holds the address of the next instruction to be executed, while the instruction register (IR) holds the encoded instruction. Upon fetching the instruction, the program counter is incremented by one “address value” (to the location of the next instruction).

Why is an instruction register not accessible to programmers?

IR (Instruction Register) is a special purpose register, which is used to receive the 8-bit opcode portion of an instruction. It is not accessible to the programmer. What it means is that there are no instructions by which the programmer can load it with values of his choice.

What instruction register contains?

An instruction register contains the actual or encoded instructions, not the addresses. It’s part of the CPU control unit. We can find several registers in the CPU control unit like index register, data register, and instruction register.

What kind of instructions usually affect the program counter?

24. What kind of instructions usually affect the program counter?

• Push & Pop.
• Call & Jump.
• Call & Return.
• Return & Jump.