Register Memory

Register memory is memory size very small but have very high-speed access. Register used to save data instructions are being processed, while the other data and other instructions waiting to processed are in main memory.

Registers in the CPU consists of :

1. Instruction Register (IR) used to save instruction are being processed
2. Program Counter (PC) is registers are used to save the address location of main memory containing the instruction being processed. During the process  progresses, the content is converted to PC main memory address containing instructions the next to be processed. This makes it possible to trace the next instruction in main memory.
3. General Purpose Registers, the registers that have a wide range of functions associated with the data being processed. For example, if used for accommodate the data being processed is referred to as the operand register, while if it is used to hold the processed result is called the accumulator.
4. Memory Data Register (MDR) the register are use to accommodate the data or instructions sent from main memory to the CPU, or to accommodate data saved to main memory as a result of CPU processing.
5. Memory Address Register (MAR) used to hold data or address instructions in the main memory to be taken or to be placed.