Microcontroller knowledge - structure and related companies

Overview

The vast majority of current microcontrollers are based on the von Neumann architecture, which clearly defines the four basic parts required for an embedded system: a central processing unit core, program memory (read-only memory or flash memory), data memory (random access memory), one or more timers/counters, and input/output ports for communicating with peripheral devices and expansion resources - all integrated on a single integrated circuit chip.

The reason why single-chip microcomputers are different from general-purpose central processing unit chips is that they are generally easy to be combined with the smallest external support chips to form a working computer. In this way, it is easy to implant the single-chip microcomputer system into the device to control the device. In recent years, in order to use different word widths for instructions and data and to increase the processor pipeline speed, the Harvard structure has gradually been widely used in microcontrollers and digital signal processors (DSP).

Traditional microprocessors do not allow this. To complete the work of a single-chip microcomputer, it must be connected to some other chips. For example, because there is no data storage on the chip, some RAM storage chips must be added. Although the capacity of the added storage is very flexible, it must be added at least. In addition, many connections need to be added to transfer data between chips. Compared with the above situation, the work of a single-chip microcomputer is relatively independent. A typical microcontroller only needs a clock generator and a small amount of RAM and ROM (or EPROM, E2PROM) to work under software and crystal oscillators. At the same time, microcontrollers have a wealth of input and output devices, such as analog-to-digital converters (ADCs), timers, serial ports, and other serial communication interfaces, such as I2C, SPI (serial peripheral interface), CAN (controller area network), etc. Usually, these integrated devices can be operated by special instructions.

The clock frequency of a microcontroller is usually lower than that of contemporary computer chips, but it is inexpensive and can provide ample program memory and rich on-chip interfaces. There are many manufacturers of microcontrollers of certain architectures, such as the 8051 series and the Z80 series. Some modern microcontrollers support some built-in high-level programming languages, such as BASIC, C, C++, etc.

Number of bits in a microcontroller

According to the width of the bus or data register, single-chip microcomputers are divided into 4-bit, 8-bit, 16-bit and 32-bit single-chip microcomputers. 4-bit single-chip microcomputers are mostly used in the control of household appliances such as refrigerators, washing machines, and microwave ovens; 8-bit and 16-bit single-chip microcomputers are mainly used in general control fields and generally do not use operating systems; 32-bit single-chip microcomputers are used in complex processing occasions such as network operations and multimedia processing, and generally use embedded operating systems.

Common microcontrollers

Microchip's PIC series is the industry leader in terms of shipments; Atmel's 51 series and AVR series are numerous and widely supported; Texas Instruments' MSP430 series is famous for its low power consumption and is often used in medical electronic products and instrumentation; Renesas microcontrollers are widely used in Japan.

ARM Series MCU

AVR series (Atmel)

Atmel AT91 series (ARM processors, etc.)

AT90 series – AVR (Atmel's high-performance RISC 8-bit microcontroller, old product)

ATmega series – AVR (Atmel's high performance RISC 8-bit microcontroller, new product)

ATXmega series – AVR (Atmel's high performance RISC 32-bit microcontroller, new product)

Atmel AT89 series (Intel 8051/MCS51 architecture 8-bit microcontroller)

MARC4

Cypress MicroSystems

CY8C2xxxx (PSoC)

Freescale Semiconductor

8-bit

68HC05 (CPU05)

68HC08 (CPU08)

68HC11 (CPU11)

16-bit

68HC12 (CPU12)

68HC16 (CPU16)

Freescale DSP56800 (DSPcontroller)

32-bit

Freescale 683XX (CPU32)

MPC500

MPC 860 (PowerQUICC)

MPC 8240/8250 (PowerQUICC II)

MPC 8540/8555/8560 (PowerQUICC III)

Holtek (Holtek Semiconductor)[page]

HT48FXX Flash I/O type

HT48RXX I/O type

HT46RXX A/D type

HT49RXX LCD type

Intel

8-bit

8XC42

MCS48

MCS51: Intel 8051 series has a long history, many compatible products, and is widely used

8xC251

16-bit

MCS96 Series

MXS296

32-bit

i960

Microchip's PIC microcontroller family

8-bit : PIC10 PIC12 PIC16 PIC18

16-bit : PIC24F PIC24H dsPIC30 dsPIC33

32bit: PIC32 (using MIPS M4K core architecture)

National Semiconductor

COP8

CR16

NEC

78K

NXP Semiconductors (NXP Semiconductors, newly established by Philips with Philips Semiconductors as the base)

LPC2000

LPC900

LPC700

Parallax, Inc.

BASIC Stamp

Renesas Technology Series MCU

Renesas 16-bit

Renesas M16C Series

Renesas M32C Series

Renesas R8C Series

Renesas M16C/Tiny Series

Renesas R8C/Tiny Series

Renesas H8/Tiny Series

STMicroelectronics

STM32 series (ARM Cortex-M3 series, 32-bit)

STM8 series (independent RISC instruction set, 8-bit)

SyncMOS MCU Series

SM59RXXA2 8-bits 1T(RISC)

SM59DXXG2 8-bits 6T(ISP)

SM59XX 8-bits 12T(ISP)

SM89XX 8-bits 12T(Traditional 8051)

SM79XX 8-bits 12T(Customization)

PADAUK Yingguang Technology's full range of MCUs (multi-core MCUs)

P201CS/CD 8-bits

P211CS/CD 8-bits

p232CS/CD 8-bits

P234CS/CD 8-bits[page]

ZiLOG

Z8

Z86E02

STC Macrochip Series MCU

STC89C series 6T/12T enhanced single chip microcomputer (Intel 8051 architecture, with external bus)

STC11F/11L series 2T enhanced single chip microcomputer (Intel 8051 enhanced architecture, no external bus program support)

STC12C/12LE series 2T enhanced MCU (Intel 8051 enhanced architecture, no external bus program support)

STC15C/15LE series 2T Enhanced MCU (Intel 8051 enhanced architecture, no external bus program support, under development)

Kernel-IC Huaxin MCU LS Series

LSx051 series 12T dual-core microcontroller (Intel 8051 architecture, no external bus)

LSx151 series 12T triple-core microcontroller (Intel 8051 architecture, no external bus)

LS052A series 6T triple-core microcontroller (Intel 8051 architecture, no external bus)

Other series of microcontrollers

Msp430 series microcontroller

8098, 80196 series microcontrollers

AT8P5X Series MCU

CZG8000 Series MCU

Development of single chip microcomputer

In the past, assembly language was mostly used in the software development of single-chip microcomputers, but now more and more C language is used, or BASIC language and other languages ​​more suitable for beginners are used. Some integrated development environments support C++. Single-chip microcomputer software testing requires the use of single-chip microcomputer developers or simulators.

With the development of technology, after 2000, many MCUs have come with ISP (in-circuit programming) or support IAP, which has completely changed the traditional development model, making it possible to develop MCU systems without damaging the pins of the chip, accelerating the launch of products and reducing R&D costs, shortening the time from design, manufacturing to on-site debugging, simplifying the production process, and greatly improving work efficiency. This type of MCU includes AT89S series MCU, AVR series MCU, etc.

hardware

Development boards can further simplify the process of program development and burning. Development boards may contain actual chips or emulators. Connect the computer and development board through the matching download cable, write the program on the computer and download it to the development board. Programmers will be used for mass production.

Software Development Environment

Some well-known microcontroller development environments are:

Microchip's MPLAB IDE can be used for development and debugging of the company's full range of microcontrollers. In addition to supporting the company's ASM assembler C language compiler, it also supports many third-party compilers.

ARM's μVision integrated development environment (formerly a product of Keil, which was acquired by ARM in 2005) includes an assembler and a C compiler, and can be used for 51 microcontroller and ARM development.

PROTEUS

Proteus software is the first choice for beginners. It is a commercial version of circuit design and simulation software from Labcenter Electronics. It includes software modules such as ISIS and ARES. The ARES module is mainly used to complete PCB design, and the ISIS module is used to complete the layout and simulation of circuit schematics.

Proteus software simulation is based on VSM technology. Its biggest difference and advantage from other software is that it can simulate a large number of single-chip microcomputer chips, such as MCS-51 series, PIC series, etc., and even ARM processors, as well as single-chip microcomputer peripheral circuits, such as keyboards, LEDs, LCDs, etc. The software also comes with some cases and rich help files.