CPU architecture.

Jordan Mock
3 min readFeb 13, 2022

Registers

Registers are integrated circuits that hold binary information. Registers shift, accept and dispense information in different ways depending on its type. SISO or series in series out registers shift information in a que that spans the length of the register. PIPO or parallel in parallel out registers accept multiple bits of information at once , shifting Said information from side to side in parallel.

Clock

In the schematics we have a 555 timer and just below is an example of a crystal quarts oscillator. Both of these are forms of clocks. Clocks propagate the computer By turning a signal high then dissipating the accumulated electricity in such a way that sets the pulse low depending on the respective clock type.

program counter

The program counter (PC) is a register that manages the memory address of the instruction to be executed next. It is sometimes known as the Instruction address register

Data Bus

A bus is a group of wires that move binary information throughout the computer. We can instruct the data bus to read information meaning we tell a specified register of the cpu to read the information we store on the data bus. Write is when we tell a register to write information to the data bus. Enable is when we activate our enable wire which allows the instructions read or write to actually occur. A data bus program will say something like register A read enable .I this case the register A would accept the information from the data bus.

RAM

Random-access memory is a form of memory. It is comprised of a lattice of multiplexers and registers. The multiplexers allow us to access data from a specified location in ram

Control Unit

A CU typically uses a binary decoder to convert coded instructions into timing and control signals that direct the operation of the other units. The control unit receives its instructions from the instruction memory register then decodes those instructions and has then executes those instructions

Serial I/O controller

I/O controllers allow peripherals like a keyboard or a mouse to communicate with the cpu. In other wards the I/O acts as a translator between the device and the cpu.

Accumulator

The accumulator is a register in which intermediate arithmetic logic unit results are stored.

Arithmetic logic unit “ALU”

The ALU takes values from the register and performs mathematical operations or logic operations on them and saves the results in memory.

Instruction register

The instruction set register is the register that contains the diffrent commands you

might want to us in an operation. here are some examples of computer instructions.

  • ADD — Add two numbers together.
  • COMPARE — Compare numbers.
  • IN — Input information from a device, e.g., keyboard.
  • JUMP — Jump to designated RAM address.
  • JUMP IF — Conditional statement that jumps to a designated RAM address.
  • LOAD — Load information from RAM to the CPU.
  • OUT — Output information to device, e.g., monitor.
  • STORE — Store information to RAM.

Fetch phase

This is the first phase of our cycle. In this part the control unit gets a set of instructions from memory.

Decode phase

In this stage our control unit now having taken in an instruction set, translates those instruction into commands and passes those commands to the ALU

Execute phase

At this point the ALU takes the output and saves it into memory.

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