1. Core Architecture Features
1. System on Chip (SoC) Integration
- Module Aggregation: Integration of CPU, RAM, ROM, I/O, timers, ADC/DAC, etc. on a single chip
- Typical Case: STM32F407 integrates ARM Cortex-M4 core + 1MB Flash + 192KB RAM + rich peripherals
2. Memory Structure
- Program Memory (ROM/Flash)▶ Stores firmware (e.g., LED control code)▶ Capacity: 8KB~2MB (e.g., 32KB Flash of Arduino Uno)
- Data Memory (RAM)▶ Temporarily stores runtime data (e.g., sensor readings)▶ Capacity: 1KB~256KB (e.g., 520KB RAM of ESP32)
3. Bus Architecture
- Harvard Architecture▶ Separate program and data buses → Parallel processing of instructions and data (e.g., STM32 series)
- Von Neumann Architecture▶ Shared program/data bus → Simplified design (e.g., 8051 series)
2. Functional Module Composition
1. Central Processing Unit (CPU)
- Bit Classification
Type Typical Example Application Scenario 8-bit AT89C51 Basic control (e.g., toys) 16-bit MSP430 Low-power devices (e.g., blood glucose meters) 32-bit STM32F7 Complex systems (e.g., robots)
2. Peripheral Interfaces
- General I/O (GPIO)▶ Configurable as input/output mode (e.g., controlling LED on/off)
- Communication Interfaces▶ UART (serial), SPI (high-speed communication), I2C (multi-device bus)
- Analog to Digital Conversion (ADC)▶ 10-bit to 16-bit precision (e.g., reading potentiometer analog values)
3. Clock and Power Management
- Multiple Clock Sources▶ Internal RC oscillator (low cost) + external crystal oscillator (high precision)
- Low Power Modes▶ Sleep/standby modes (e.g., MSP430 sleep current < 1μA)
3. Physical Structure Characteristics
1. Packaging Types
- Common Types▶ DIP (Dual In-line Package): Suitable for learning boards (e.g., 8051)▶ QFP (Quad Flat Package): High-density integration (e.g., STM32F103)▶ BGA (Ball Grid Array): Ultra-miniaturization (e.g., ESP32-C3)
2. Pin Multiplexing
- Multi-functional Pins▶ A pin can be configured as GPIO/UART/ADC, etc. (e.g., STM32’s PA5 can be used as general IO or timer output)
3. Expansion Capabilities
- External Bus Interfaces▶ Supports external memory (e.g., NOR Flash) or peripherals (e.g., TFT screens)
4. Comparison with General Computers
| Dimension | Microcontroller | PC / Server |
|---|---|---|
| Integration Level | Chip-level full functional integration | Mainboard + independent components |
| Storage Architecture | On-chip ROM/RAM as main | Hard disk + separate memory |
| I/O Control | Directly drives peripherals (e.g., servos) | Indirectly controlled through the operating system |
| Power Consumption | Milliwatt level (e.g., 3mA of PIC16F18346) | Hundreds of watts |
📌 SummaryMicrocontrollers achieve a perfect balance of miniaturization, low power consumption, and real-time control capabilities through a highly integrated system-on-chip architecture. Their modular design ensures basic control needs while supporting complex system development through flexible expansion interfaces, making them a core technology in the embedded field.
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【Complete Set of Hardware Learning Materials Collection】
