ALU, Data Path, and Control Unit

By : Manglika Tripathi

Updated : Feb 26, 2021, 5:38

A combinational digital circuit responsible for performing bitwise and arithmetic operations on integer binary numbers is called an arithmetic logic unit. The central processing unit is divided into two sections - the data section and the control section. The data section is nothing but an alternate name for the data path. The data path is a combination of registers, ALU, and interconnecting bus. Every bit in the datapath is identical functionally. The data path performs several operations on data items.

The control unit decodes the opcode and operand bits in the instruction register. It then generates the control signals required to drive every single hardware in the CPU to perform a series of little operations that includes instruction. These topics are also important for other competitive exams like ESE, BARC, ISRO, etc. Let us see the important ALU, Data Path, and Control Unit topics for GATE CS.

Important ALU, Data Path, and Control Unit Topics for GATE CS

Going through the ALU, Data Path, and Control Unit syllabus for GATE and ALU, Data Path, and Control Unit GATE questions are important topics.

Topic

Description

CPU Organisation

Based on ALU data paths, the CPU organisation is classified as stack CPU, Accumulator CPU, and General Register CPU.

Memory Interfacing

The integration of the CPU and memory unit is memory interfacing.

Design of Control Unit

The control unit initialises a series of micro-operations. In this section, you will study the block diagrams and other concepts related to the control unit.

Interrupt Handling

After the execution of every instruction, a test checks, if there are any, interrupts pending. There is a sequence of steps followed if interrupts are detected.

Tips to prepare ALU, Data Path, and Control Unit for GATE

  1. For the GATE exam preparation, you should first go through the ALU, Data Path, and Control Unit GATE syllabus.
  2. As you start studying, make your ALU, Data Path, and Control Unit GATE notes simultaneously. If you don’t have the habit of preparing notes for yourself, you can refer to the ALU, Data Path, and Control Unit notes for GATE pdf available online.
  3. Once you are done with the preparation, you can start attempting the ALU, Data Path, and Control Unit MCQ questions. You can find ALU, Data Path, and Control Unit MCQ pdf online. You can identify your weak topics and prepare it again.
  4. You can then go for an ALU, Data Path, and Control Unit online quiz and take the ALU, Data Path, and Control Unit online test provided by BYJU'S Exam Prep.
  5. You can make this subject crystal clear and revise the topic by referring to the online ALU, Data Path, and Control Unit GATE questions and answers pdf.

Importance of ALU, Data Path, and Control Unit for GATE

  1. The ALU, data path, and control unit plays a vital role in computers, and hence it is an important topic to study from computer organisation and architecture.
  2. ALU, Data Path, and Control Unit for computer science is a topic from the computer organization and architecture. Its weightage in the GATE exam ranges from 5 to 11 marks.
  3. In previous GATE exams, a total of seven questions have been asked from the topic “ALU, Data Path, and Control Unit”.
  4. This is also an important topic for university semester exams and other competitive exams like ESE, BARC, ISRO, etc.

Most Recommended ALU, Data Path, and Control Unit Books for GATE

A good ALU, Data Path, and Control Unit book helps to understand difficult concepts easily. Given below are the most recommended ALU, Data Path, and Control Unit books.

Book

Author

Computer Organization

Carl Hamacher, Zvonko Vranesic, Safwat Zaky

Computer Organization and Architecture

William Stallings

Computer Organization and Design

David A. Patterson

Why Prepare ALU, Data Path, and Control Unit with BYJU'S Exam Prep?

BYJU'S Exam Prep is an online exam preparation platform to help you in achieving your GATE score goal effortlessly. You can download the BYJU'S Exam Prep app to get the best collaborative and brainstorming ALU, Data Path, and Control Unit study material for GATE CS. You can also get access to ALU, Data Path, and Control Unit quiz, tests, and MCQs. You should prepare ALU, Data Path, Control Unit, and other GATE topics from BYJU'S Exam Prep to ace your exams and achieve milestones. You can also avail of expert guidance via live sessions.

FAQs

Q. What is the use of a program counter?

A: A program counter is used for holding the address of the next instruction.

Q. What is an address bus?

A: Address bus carries the address of the main memory location from where the data can be accessed.

Q. What is a single-cycle data path and multi-cycle data path?

A: In a single-cycle datapath, every single instruction is executed in one clock cycle whereas, in a multi-cycle data path, every single instruction is executed in multiple clock cycles.

Q. What is the relation between control words, micro-routine, and micro-instruction?

A: A word whose every single bit represents various control signals is called a control word. A series of control cords corresponds to the control sequence of a machine instruction that gives the micro-routine. And every single control word in micro-routine is called micro-instructions.

Q. Compare Horizontal and Vertical Micro-programming.

A: (a) Horizontal microinstruction is faster than vertical microinstruction, but it requires greater length microinstructions. (b) Horizontal programming allows more than one signal to be activated at the same time without any hardware modification. Whereas, vertical micro-programming requires modification to the instruction format.