Introduction to Microcontroller Minimum System
What is Microcontroller Minimum System
Microcontroller Minimum System refers to the simplest circuit system composed of microcontroller and external devices, which includes basic circuits such as microcontroller, crystal, power supply and reset circuit.
Microcontroller minimum system is the foundation of microcontroller development and microcontroller application. Mastering the principles and design methods of the microcontroller minimum system is of great significance for learning microcontroller programming and applications.
Composition of the microcontroller minimum system
The microcontroller minimum system consists of basic circuits such as microcontroller, crystal, power supply and reset circuit.
Microcontroller is the core of the whole system, which is a kind of integrated circuit containing functional modules such as central processing unit (CPU), memory (ROM and RAM), input/output interfaces (I/O ports), and timer counter.
The crystal oscillator is the clock source for the operation of the microcontroller, which provides the clock signal for the microcontroller. A microcontroller needs a clock signal to synchronize its internal operations. The higher the frequency of the crystal, the faster the microcontroller will run.
The power supply is the source of energy for the microcontroller’s smallest system, which provides the electrical power needed by the microcontroller and external devices. The power supply can be a DC or AC power source or a battery.
The reset circuit is an important part of the microcontroller’s minimum system, which is used to zero out the internal state of the microcontroller when it is powered up or reset to the initial state. The reset circuit is usually composed of a reset circuit chip, capacitors and resistors, and other devices.
Design of the microcontroller minimum system
The design of the microcontroller minimum system needs to consider the following aspects:
Selection of microcontroller
Selection of the microcontroller needs to consider the application scenarios and needs, to determine the microcontroller model and parameters. Commonly used microcontrollers are 51 series, AVR series, PIC series and so on.
Selecting a crystal
Selecting a crystal needs to consider the clock frequency and precision of the microcontroller, and generally choose a 4MHz or 8MHz crystal.
Designing the power supply
Designing the power supply needs to consider the power requirements and voltage requirements of the microcontroller and external devices, generally use 5V DC power supply.
Designing the reset circuit
Designing the reset circuit needs to consider the stability and reliability of the reset circuit, generally use the reset circuit chip and capacitors and resistors and other devices.
Operating Steps of MCU Minimum System
The operating steps of MCU minimum system are as follows:
1. Determine MCU Model and Parameters
Choose the MCU model and parameters according to the application scenarios and requirements.
2. Select crystal
Select 4MHz or 8MHz crystal according to the clock frequency and precision of the microcontroller.
3. Design the power supply
Design the 5V DC power supply according to the power demand and voltage demand of the microcontroller and external devices.
4. Design reset circuit
Design reset circuit chip and capacitor and resistor devices according to the stability and reliability of the reset circuit.
5. Connect the circuit
Connect the microcontroller, crystal, power supply and reset circuit and other devices according to the circuit diagram.
6. Write the program
Write the program and burn it into the microcontroller according to the model and parameters of the microcontroller.
7. Debugging the program
Connect the microcontroller minimum system to the computer, use the development tools for debugging, and check whether the program runs normally.