instruction register
nounUK /ɪnˈstrʌkʃən ˈrɛdʒɪstə/
US /ɪnˈstrʌkʃən ˈrɛdʒɪstər/
A small storage spot inside a computer that holds the next command it needs to do.
The processor copied the new command into the instruction register before decoding it.
OTHER MEANINGS
2. A register in a CPU that temporarily stores the instruction being executed.
During the fetch cycle, the instruction register receives the opcode from memory.
3. A hardware latch used to hold a machine instruction between fetch and decode stages.
The instruction register feeds the control logic that drives the datapath.
4. In some architectures, a register that holds the full instruction word including operands.
The instruction register width matches the machine's instruction word size.