Various CPU registers in computer architecture
Registers are used to store, accept, transfer instructions and data that being used immediately by the Central Processing Unit (CPU). It's comes at the top of the memory hierarchy, and are the fastest way for the system to manipulate data. Registers are created from the fastest memory cell. There are several types of registers that are used to accomplish different tasks.
Some of the most commonly used registers are -
- Accumulator (AC)
- Data Register (DR)
- Address Register (AR)
- Program Counter (PC)
- Memory Data Register (MDR)
- Index Register (IR)
- Memory Buffer Register (MBR)
Registers are used to perform various types of operations. Like when we are working on computer system these registers are used by CPU to perform operations. When we gives any input to computer then input will be stored in CPU memory which is register and after taking input CPU will perform some operation on given input, After processing it gives us a result which is also stored in registers. So that the registers can be used by the Central Processing Unit (CPU) to process the data given by the computer user.
Register Display :-
1) Get
Fetch operation is used to take or fetch the data given by the user and the instructions which are stored in RAM (main) memory will be fetched using CPU registers.
2) Decode
Decode operation is used to interpret means that the data is decoded i.e. CPU will check or find out which operation is to be performed on the instructions given by the user.
3) Execute
The execution operation is done by the Central Processing Unit (CPU). And the results which are produced by the CPU are then stored in registers or memory and then displayed on the monitor screen.
CPU registers and their functions are given below -
Accumulator Register (AC)
The accumulator register is placed inside the ALU (Arithmetic Logic Unit), it is used while performing arithmetic and logical operations of CPU ALU. The control unit (CU) stores data values taken from RAM memory in the accumulator for arithmetic or logical operations. This register contains the initial data to be operated on, the intermediate results and the final results of the operations. The final result is transferred to the RAM memory through the MBR (Memory Buffer Register).
Data Register (DR)
This register is used to temporarily store data during transmission from a peripheral device to a microcomputer.
Input/Output Address Register (I/O AR)
The I/O address register is used to specify the address of a special input output device and it also saves the address of the data which is saved in the main memory.
Program Counter (PC)
Program counter register is also called instruction pointer register. This register is used to store the address of the next instruction to be received by the CPU for execution. When the instruction is received, the value of IP is increased by one. This register always tells or holds the address of the next instruction to be received by the CPU.
Memory Address Register (MAR)
This register stores the address of the memory where CPU wants to read data or write data. When the CPU wants to store some data in memory or read data from memory, it places the address of the required memory region or location in the MAR.
Memory Buffer Register (MBR)
This register holds the contents of data or instructions. read from, or written to, memory. The contents of the instruction held in this register are transferred to the instruction register, while the contents of the data are transferred to the accumulator or I/O register. To put it another way, we can say that registers are used to save the data or instructions which is coming from memory or going into memory.
Instruction Register (IR)
Once an instruction is received from the main memory, it is stored in the instruction register. The control unit takes instructions from this register, decodes and executes it by sending a signal to the appropriate component of the computer to complete the task.
Accumulator Register (AC)
The accumulator register is located inside the ALU, it is used during the arithmetic and logical operations of the ALU. The control unit stores the data values received from the main memory in the accumulator for arithmetic or logical operations. This register contains the initial data for the operation, the intermediate result and the final result of the operation. The final result is transferred through the MBR to the main memory.
Stack Control Register (SCR)
The stack control register represents a set of stack memory blocks. The data in these blocks is saved and retrieved in a sequence, i.e. First In and Last Out (FILO). The stack control register is used to manage the stack in memory. And the size of the register is 2 or 4 bytes.
Also read : Logic Gates and It's Types - Learn With AVRK
