basic components of a computer

Features of a von Neumann computer

Composition of five major components
1. calculator
2. memory
3. controller
4. input device
5. output device
Instructions and addresses are stored in the memory on the same level, and are accessed by address
Instructions and data are represented in binary
Instructions consist of opcodes (indicating what to do) and address codes
stored program, instructions are stored sequentially in the memory
Calculator-centric

Hardware block diagram of the processor core

The above is a computer hardware block diagram with the arithmetic unit as the core

The arithmetic unit completes arithmetic operations and logical operations, and temporarily stores the intermediate results of the operation in the arithmetic unit
Memory stores data and programs
The controller controls, directs the input, operation, and processing of calculation results of programs and data
Input devices convert information familiar to humans into information recognized by machines
Output devices convert the results of machine operations into a form familiar to humans

Solving an example problem with a computer involves two major steps:

Preparation
- Build a mathematical model
- Determine the calculation method
- Compile the problem-solving program: program (all steps) + instruction (each step)
Run on the machine

The basic composition of memory:

Storage body (building) -> storage unit (room, a string of binary, storage word) -> storage element (bed, a binary)
The MAR
memory address register stores the address of the storage unit, and the number of digits corresponds to the number of storage units (for example, MAR is 10 bits, then there are 2^10=1024 units, which is recorded as 1K)
MDR
memory data register, storing the code taken out from a storage unit or ready to be stored, the number of digits is equal to the storage sub-length

The arithmetic unit includes at least 3 registers (accumulator + multiplier register + operand register) and 1 arithmetic logic unit

register	addition	subtraction	multiplication	division
ACC	summand and sum	minuend and difference	product high	dividend and remainder
MQ			Multiplier and Product Low	business
X	addend	subtrahend	Multiplicand	divisor

The controller is the center, directing the various components to coordinate their work:

Fetch , command memory to read an instruction
Analyze , point out the operation corresponding to the instruction, and specify the address of the operand according to the addressing characteristics
Execution , completes the operation based on the operand address and the opcode of the instruction

The basic composition of the controller:

The program counter (PC)
stores the address of the instruction to be executed, and has a direct path with MAR, which can automatically add 1 to form the next instruction address
The instruction register (IR)
stores the current instruction, from the MDR
- IR sends the opcode to CU to analyze the instruction, denoted as OP(IR)->CU
- IR sends the address code to MAR, denoted as Ad(IR)->MAR
Control Unit (CU)
CU analyzes the operation required by the current instruction, and issues various bit micro-operation commands to control all controlled objects

Arithmetic Logic Unit, referred to as logic unit, is used to complete arithmetic and logic operations↩︎
Control Unit, which interprets the instructions in the memory and issues operation commands to execute the instructions↩︎
Store programs and data, and exchange information directly with the CPU↩︎