Introduction to introductory knowledge of microcontroller developmen

1. 51 microcontroller introduction

51 microcontroller is the collective name for all microcontrollers compatible with Intel 8031 instruction system.

The originator of this series of microcontrollers is Intel's 8004 microcontroller. Later, with the development of Flash ROM technology, the 8004 microcontrollers made great progress and became one of the most widely used 8-bit microcontrollers, whose representative model is ATMEL's AT89 series is widely used in industrial measurement and control systems. Many companies have 51 series of compatible models launched. 51 microcontroller is a basic introduction to a microcontroller or the most widely used one.

Main product representatives:

(1) Intel: 80C31, 80C51, 87C51, 80C32, 80C52, 87C52, etc..

(2) ATMEL: 89C51, 89C52, 89C2051, 89S51 (RC), 89S52 (RC), etc..

(3) Philips, Huabang, Dallas, Siemens, etc...

(4) STC microcontrollers: 89c51, 89c52, 89c516, 90c516, etc.

2. mainstream microcontroller types in the market

The following are the mainstream microcontrollers currently on the market.

(1) 8051 microcontroller

Intel first introduced the 8051 microcontrollers. Intel will 80C51 core rights, patent swap, or give to many of the world's leading IC manufacturers, so the 80C51 microcontroller has become a large family of chip manufacturers to support, collectively known as the 80C51 series of microcontrollers. Objective facts show that the 80C51 has become the mainstream of 8-bit microcontrollers.

(2) AVR microcontroller

AVR microcontroller is an enhanced RISC (Reduced Instruction Set CPU) streamlined instruction set high-speed 8-bit microcontroller with built-in Flash developed by ATMEL in 1997. It can be widely used in various fields such as external computer equipment, industrial real-time control, instrumentation, communication equipment, and home appliances.

The biggest feature of the AVR microcontroller is the streamlined instruction set microcontroller, execution speed, in the same oscillation frequency is the fastest 8-bit MCU in a microcontroller.

(3) PIC microcontroller

PIC microcontroller is a product of Microchip. It is also a kind of compact instruction-type microcontroller. The number of instructions is relatively small. The mid-range PIC series has 35 instructions only. The low range only has 33 instructions.

It is suitable for high usage, low-grade products, and price sensitivity. It is widely used in office automation equipment, consumer electronics, telecommunication, intelligent instruments and meters, automotive electronics, financial electronics, and industrial control.

The biggest characteristic of PIC is that it does not engage in simple function accumulation, but from the practical point of view, pays attention to the performance and price ratio of the product, and relies on the development of a variety of models to meet the requirements of different levels of applications. Dozens of models from low to high PIC series can meet various needs. Among them, the PIC12C508 microcontroller has only 8 pins, the smallest microcontroller in the world.

(4) MSP430

MSP430 series microcontroller is a 16-bit ultra-low power, with a compact instruction set (RISC) mixed-signal processor (Mixed Signal Processor) that TI began to market in 1996.

The MSP430 microcontroller is called a mixed-signal processor because of its practical application requirements, the integration of several different functions of analog circuits, digital circuit modules, and microprocessors on a single chip to provide a "single-chip" solution. This microcontroller series is mostly used in portable instrumentation that requires battery power.

MSP430 series microcontroller is a 16-bit microcontroller with fast computing speed and ultra-low power consumption. MSP430 series microcontroller power supply voltage is 1.8-3.6V voltage.

(5) ARM processor

ARM that the British ARM company's kernel chip as the CPU, while attaching other peripheral functions of the embedded development board to evaluate the function of the kernel chip and research and development of the products of various technology-based enterprises.

ARM is a 32-bit Reduced Instruction Set (RISC) processor architecture. ARM processors are widely used in many embedded system designs. ARM processors are characterized by fixed instruction length, high execution efficiency, low cost, etc.

ARM microprocessors have spread throughout industrial control, consumer electronics, communication systems, network systems, wireless systems, and other product markets. ARM technology-based microprocessor applications occupy about 32-bit RISC microprocessors, more than 75% of the market share. ARM technology is gradually penetrating all aspects of our lives.

ARM microprocessors currently include the following families and other manufacturers' processors based on the ARM architecture. In addition to the common features of the ARM architecture, each family of ARM microprocessors has its characteristics and application areas.

• ARM7 Series
• ARM9 Series
• ARM9E Series
• ARM10E Series
• ARM11 Series
• Cortex Series: The Cortex family of processors is based on the ARMv7 architecture and is divided into three categories, Cortex-M, Cortex-R, and Cortex-A. The technology used in the v7-based Cortex processor family differs depending on the application area. The v7A-based ones are called the "Cortex-A series.
• SecurCore Series
• OptimoDE Data Engines
• Intel's XScale
• Intel's StrongARM ARM11 Series

3. Difference between FPGA and microcontroller

(1) FPGA and microcontroller in the concept of the difference

Microcontroller:

The microcontroller can be understood as a microcomputer integrated on a single chip with an operator, controller, memory, bus, and input and output devices. Using the way to store the program execution, the programming of the microcontroller is to write the program to the ROM. After powering up, the program in the ROM will be like the program in the computer memory to get executed line by line.

Microcontrollers are also called microcontrollers (MCUs) because of their strong interface performance, making them ideal for industrial control.

FPGAs:

FPGA is a chip with a lower level of control, so it has more freedom. The programming of FPGA is translated into the connection table inside the FPGA after compilation, which is equivalent to a large number of basic digital devices such as with/without gates, non-gates, flip-flops (you can use with/without gates to form it), and the programming determine how many devices are used and how they are connected. As long as the FPGA is large enough, these digital devices can theoretically form all digital systems, including microcontrollers and CPUs.

FPGAs emerged as a semi-custom circuits in the field of application-specific integrated circuits (ASICs), addressing the shortcomings of custom circuits and overcoming the shortcomings of the limited number of gates of the original programmable devices.

(2) FPGA and microcontroller in the structure of the difference

The microcontroller is a microprocessor, similar to the computer CPU. It generally uses the Harvard bus structure, or the von Neumann structure, the programming of the microcontroller to a large extent to take into account its structure and the role of each register. The microcontroller is more widely used and generally used in the control pipeline, and you can see things daily!

FPGA is a lookup table structure; the program does not have to consider the structure of the chip to pay attention to the timing of the problem. Its structure is more complex but also very powerful, generally used in communications and other high-end occasions. At present, the FPGA is still considered an emerging industry. Of course, its price is also much higher than the microcontroller!

The microcontroller is a microcontroller. The microcontroller is the chip formed by loading the module software to achieve a certain function; FPGA is used to design the chip.

(3) the difference in speed between FPGA and microcontroller

Because it is a hardware circuit, the operation speed directly depends on the crystal speed. The system is stable, especially suitable for high-speed interface circuits. Microcontroller due to single-threaded, even the commonly used M3 series pipeline is a single-threaded execution. Program statements need to wait for the microcontroller cycle to execute.

(4) the essence of the difference between microcontrollers and FPGAs

The difference between FPGA and microcontroller is essentially between software and hardware. FPGA is more oriented to hardware circuits, while the microcontroller is more oriented to software.

Microcontroller design is in the software category; its hardware (microcontroller chip) is fixed, and the software programming language describes the execution of software instructions on the hardware chip;

FPGA design is in the hardware category; its hardware (FPGA) is programmable and is a process of customizing the integrated circuit on the FPGA chip through a hardware description language;

4. DSP and microcontroller difference

From the point of view of implementing computing, microcontroller, ARM and DSP can all be called CPUs.

DSP is a general-purpose digital signal processor, a unique microprocessor, and a device that processes a large amount of information with digital signals. It is not only programmable but also has a real-time operation speed of tens of millions of complex instruction programs per second, far exceeding that of general-purpose microprocessors.

DSP is suitable for digital signal processing, including FFT, digital filtering algorithms, encryption algorithms, and complex control algorithms.

DSP's real-time operation speed can reach millions of complex instruction programs per second. DSP devices than 16-bit single-chip microcontroller single instruction execution time 8 to 10 times faster, complete a multiplication and addition operation 16 to 30 times faster, the design used is the data bus and address bus separate, so that the program and data are stored in two separate spaces, allowing the instructions to take and execute instructions completely overlap, its working principle is to receive Analog signals, converted to digital signals of 0 or 1, and then modify, delete, and strengthen the digital signal, and decode the digital data back into analog data or actual environment format in other system chips, its powerful data processing capabilities and high operating speed, are the two most commendable features.

DSP chips, because of their high computing power, fast speed, small size, and high flexibility using software programming, provide an effective way to engage in various complex applications. Its main application is the fast real-time implementation of various digital signal processing algorithms.