The document discusses the control unit (CU) of a computer's central processing unit (CPU). It explains that the CU controls instruction execution sequence, interprets instructions, guides data flow, regulates timing, and handles tasks like fetching, decoding, and storing results. The CU has three main components: sequential logic, control unit registers and decoders, and control memory where microprograms are stored. The document also compares hardwired control units, which have fixed circuitry, to microprogram control units, which use replaceable microprograms stored in control memory.

1. Organisasi dan Arsitektur
Komputer
Ajeng Savitri Puspaningrum, M.Kom
Pertemuan 7

2. Control Unit (CU)

3. Explaining Cus element
Explaining the HCU and MCU

4. Structure - The CPU
Computer Arithmetic
and
Login Unit
Control
Unit
Internal CPU
Interconnection
Registers
CPU
I/O
Memory
System
Bus
CPU

5. CU - Function
Controls sequential instruction execution
Interprets instructions
Guides data flow through different computer areas
Regulates and controls processor timing
Sends and receives control signals from other
computer devices
Handles multiple tasks, such as fetching, decoding,
execution handling and storing results

6. Structure - The Control Unit
CPU
Control
Memory
Control Unit
Registers and
Decoders
Sequencing
Logic
Control
Unit
ALU
Registers
Internal
Bus
Control Unit

7. CU - Component
Sequential logic : a type of logic circuit whose output
depends not only on the present value of its input signals
but on the past history of its inputs
Control Unit Registers and Decoders : register where to
place and translate instructions that can be understood by
the CPU
Control Memory : component where programs or
microprograms, that can move the sequencing process
laying and translation of instructions, are placed

8. Control Signals
 Clock
 One micro-instruction (or set of parallel micro-instructions) per clock cycle
 Instruction register
 Op-code for current instruction
 Determines which micro-instructions are performed
 Flags
 State of CPU
 Results of previous operations
 From control bus
 Interrupts
 Acknowledgements

9. Control Signals - output
Within CPU
Cause data movement
Activate specific functions
Via control bus
To memory
To I/O modules

10. CU Design
Hardwired control (HCU)
Microprogram control (MCU)

11. Hardwired Control
Design is based on a fixed architecture. The CU is
made up of flip-flops, logic gates, digital circuits and
encoder and decoder circuits that are wired in a
specific and fixed way. When instruction set changes
are required, wiring and circuit changes must be
made.

12. Microprogram control
Microprograms are stored in a special control
memory and are based on flowcharts. They are
replaceable and ideal because of their simplicity.

13. HCU vs MCU

14. Refference
Stalling, William, Computer Organization
and Architecture, 10th Edition, Pearson,
2015
Abdurohman, Maman, Organisasi dan
Arsitektur Komputer revisi ke-4, Penerbit
Informatika, 2017

15. Terima Kasih
ajeng.savitri@teknokrat.ac.id
https://teknokrat.ac.id/en/
https://spada.teknokrat.ac.id/