【C51 Self-study Notes】Overview and Preparation

Using atmel company: AT89S52

Use the burning tool: progisp

Writing tool: Keil uVision

Development board used: Sirius TLX-1C development board

The subsequent codes have been packaged: https://download.csdn.net/download/f_zmmfs/10560847 (delete for infringement)

structure:

       It integrates an 8-bit CPU, 4K bytes of ROM, 128 bytes of RAM, four 8-bit parallel I/O ports, a full-duplex serial port, two 16-bit timers/counters, and five interrupt sources.

        CPU: Consists of calculation and control logic, as well as an interrupt system and some external special function registers

        RAM: used to store data that can be read and written, such as intermediate results of calculations, final results, and data to be displayed; (non-memory)

        ROM: used to store programs, some original data and tables;

        I/O port: Four 8-bit parallel I/O ports, which can be used as both input and output;

        T/C: Two timers/counters, which can work in both timing mode and counting mode;

        Interrupt control system for five interrupt sources

        A full-duplex UART (Universal Asynchronous Receiver Transmitter) serial I/O port for serial communication between MCUs or between MCU and microcomputer;    

        The oscillator and clock generation circuit are built in, and the quartz crystal and fine-tuning capacitor need to be connected externally. The maximum oscillation frequency depends on the model and performance of the microcontroller.

Level:

Two levels of digital circuits: 0 1

TTL level: 1——+5v 0——0v (for microcontroller)

RS232 level: 1——+12v 0——-12v (for computer serial port)

Therefore, the communication between the computer and the microcontroller requires the addition of a level conversion chip max232

Common data types:

Special data types:

Common header files:

Usually there are:

           reg51.h reg52.h math.h ctype.h stdio.h stdlib.h absacc.h

reg51.h reg52.h (define special function registers and bit registers);

math.h (defines common mathematical operations) 

Common bit operations:

>> << (bit shift right bit shift left)

    & | (bitwise AND bitwise OR)

    ^ ~ (bitwise exclusive or bitwise inversion)

Summarize:

Steps for MCU development:

1. Analyze and implement functions: split the functions into modules to implement them - what chip to use

2. Analyze the chip: study the chip manual and understand how to use the chip (parameters, key points of operation, timing diagram, examples) - how to use the chip

3. Combination chip: connect the chip to the MCU according to a certain logic, construct a complex circuit (already constructed MCU development board) - put the chips together

4. Analyze the pin diagram: Construct the information interaction logic between the MCU IO and the chip (development board schematic diagram) - study the combination principle

5. Code implementation: Control IO ports to achieve data interaction - write down your ideas