Detailed explanation of the world's seven major MCUs

　　Microcontrollers are now everywhere, with a wide variety of types, making developers overwhelmed, and the development is also quite rapid. From the 1980s, from the 4-bit and 8-bit microcontrollers at that time to the various high-speed microcontrollers now...

　　Various manufacturers have also been up and down in speed, memory, and functions. At the same time, a large number of manufacturers with representative microcontrollers have emerged: Atmel, TI, ST, MicroChip, ARM... The domestic Hongjing STC microcontroller is also remarkable...

　　The following is a comparison of the advantages and disadvantages of 51, MSP430, TMS, STM32, PIC, AVR, and STC microcontrollers and their functional performance...

　　51 single chip microcomputer

　　The most widely used 8-bit microcontroller is of course also the easiest one for beginners to learn. It was first introduced by Intel. Due to its typical structure and centralized management of perfect bus-specific registers, numerous logic bit operation functions and rich control-oriented instruction system, it can be called a "classic" of a generation, laying the foundation for the development of other microcontrollers in the future.

　　The main reasons why the 51 single-chip microcomputer has become a classic and easy-to-use single-chip microcomputer are as follows:

　　characteristic:

　　1. From the internal hardware to the software, there is a complete bit-by-bit operating system, called a bit processor, which processes bits instead of words or bytes. It can not only process certain bits of special function registers in the chip, such as transfer, set, clear, test, etc., but also perform bit logic operations. Its functions are very complete and easy to use.

　　2. At the same time, a dual-function address range is specially opened up in the on-chip RAM area, which is extremely flexible to use. This function undoubtedly provides great convenience to users.

　　3. Multiplication and division instructions, which also brings convenience to programming. Many 8-bit microcontrollers do not have multiplication functions, and when performing multiplication, you have to program a subroutine call, which is very inconvenient.

　　Disadvantages: (Although it is a classic, the disadvantages are still obvious)

　　1. AD, EEPROM and other functions need to be expanded, which increases the burden on hardware and software.

　　2. Although the I/O pins are easy to use, they have no output capability at high levels, which is also the biggest weakness of the 51 series microcontrollers.

　　3. The running speed is too slow, especially the dual data pointers. If it can be improved, it will bring great convenience to programming.

　　4. The protection capability of 51 is very poor and the chip can be easily burned out.

　　Applications:

　　At present, it is widely used in teaching occasions and occasions with low performance requirements.

　　The most commonly used devices: 8051, 80C51.

　　MSP430 MCU

　　The MSP430 series microcontroller is a 16-bit ultra-low power mixed signal processor launched by Texas Instruments in 1996. Its biggest highlight is its low power consumption and high speed. Its assembly language is very flexible, with many addressing modes and few instructions, making it easy to use. This is mainly because it integrates many analog circuits, digital circuits and microprocessors on one chip to provide a "single-chip" solution in response to actual application needs. Its rapid development and continuous expansion of its application scope are mainly due to the following characteristics…

　　characteristic:

　　1. Powerful processing capability, adopting a reduced instruction set computing (RISC) structure, with a variety of addressing modes (7 source operand addressing, 4 destination operand addressing), 27 concise core instructions and a large number of simulation instructions; a large number of registers and on-chip data memory can participate in a variety of operations; there are also efficient table lookup processing instructions; with a high processing speed, the instruction cycle is 125 ns under 8MHz crystal drive. These features ensure that a highly efficient source program can be compiled.

　　2. In terms of operation speed, it can achieve a 125ns instruction cycle when driven by an 8MHz crystal. The combination of 16-bit data width, 125ns instruction cycle and multi-function hardware multiplier (capable of multiplication and addition) can realize certain algorithms of digital signal processing (such as FFT, etc.).

　　3. Ultra-low power consumption: The reason why the MSP430 microcontroller has ultra-low power consumption is that it has its own unique features in reducing the chip power supply voltage and flexible and controllable operating clock. The power supply voltage is 1.8~3.6V. Therefore, when it runs under the clock condition of 1MHz, the current of the chip will be around 200~400uA, and the minimum power consumption in the clock shutdown mode is only 0.1uA.

　　shortcoming:

　　1. I personally feel that it is not easy to get started and is not suitable for beginners. There is also little information and you can only go to the official website to find it.

　　2. It takes up a large instruction space, because it is a 16-bit microcontroller, the program is in words, and some instructions actually take up 6 bytes. Although the program appears simple, it takes up a lot of space compared to the PIC microcontroller.

　　Applications:

　　It is widely used in low-power and ultra-low-power industrial applications.

　　The most commonly used devices: MSP430F series, MSP430G2 series, and MSP430L09 series.

　　TMS MCU

　　Here we also mention the TMS series of microcontrollers, although they are not mainstream. The 8-bit CMOS microcontroller launched by TI has multiple storage modes and multiple peripheral interface modes, which are suitable for complex real-time control occasions. Although not as good as STM32, nor as ostentatious as MSP430, the TMS370C series of microcontrollers provide cost-effective real-time system control by integrating advanced peripheral function modules and memory configurations of various chips. At the same time, it adopts high-performance silicon gate CMOS EPROM and EEPROM technology. Low operating power consumption CMOS technology, wide operating temperature range, noise suppression, coupled with high performance and rich on-chip peripheral functions, make the TMS370C series of microcontrollers have certain applications in automotive electronics, industrial motor control, computers, communications and consumer products.

　　The most widely used device: TMS370C256A.

　　STM32 MCU

　　The STM32 series of microcontrollers launched by ST are known to all industry friends as being a series of microcontrollers with the highest cost-effectiveness, and they are extremely powerful. They are based on the ARM Cortex-M core designed specifically for embedded applications that require high performance, low cost, and low power consumption, and have first-class peripherals: 1μs dual 12-bit ADC, 4Mbit/s UART, 18Mbit/s SPI, etc. They also have excellent performance in terms of power consumption and integration. Of course, compared with the power consumption of MSP430, they are slightly inferior, but this does not affect the engineers' enthusiasm for them. Due to their simple structure and easy-to-use tools combined with their powerful functions, they are well-known in the industry... Their powerful functions are mainly reflected in:

　　characteristic:

　　1.Core: ARM32-bit Cortex-M3CPU, maximum operating frequency 72MHz, 1.25DMIPS/MHz, single-cycle multiplication and hardware division.

　　2. Memory: 32-512KB Flash memory and 6-64KB SRAM memory integrated on chip.

　　3. Clock, reset and power management: 2.0-3.6V power supply and I/O interface drive voltage. POR, PDR and programmable voltage detector (PVD). 4-16MHz crystal oscillator. Embedded 8MHz RC oscillator circuit adjusted before delivery. Internal 40 kHz RC oscillator circuit. PLL for CPU clock. Calibrated 32kHz crystal oscillator for RTC.

　　4. Debug mode: Serial Debug (SWD) and JTAG interface. Up to 112 fast I/O ports, up to 11 timers, up to 13 communication interfaces.

　　The most used devices: STM32F103 series, STM32 L1 series, STM32W series.

　　PIC Microcontroller

　　PIC microcontroller series is a product of Microship in the United States. It is divided into three levels, namely basic, intermediate and advanced. It is one of the microcontrollers with the fastest market share growth. The CPU adopts RISC structure, with 33, 35 and 58 instructions respectively, which belongs to the reduced instruction set. At the same time, it adopts Harvard dual bus structure, which runs fast. It can make the access of program memory and data memory processed in parallel. This instruction pipeline structure completes two parts of work in one cycle, one is to execute instructions, and the other is to fetch the next instruction from the program memory. In this way, each instruction only needs one cycle, which is one of the reasons for high efficiency operation. In addition, the reason why PIC microcontroller has become a very popular microcontroller for a while is nothing more than the following features:

　　Features:

　　1. It has the characteristics of low operating voltage, low power consumption, strong driving ability, etc. The I/O port of the PIC series microcontroller is bidirectional, and its output circuit is a CMOS complementary push-pull output circuit. The I/O pin has added a direction register for setting the input or output state, thus solving the problem that the 51 series I/O pin is both input and output when it is at a high level.

　　2. When set to 1, it is in input state, and no matter whether the pin is at a high level or a low level, it is in a high-impedance state to the outside; when set to 0, it is in output state, no matter what level the pin is at, it is in a low-impedance state, with considerable driving capability, low-level absorption current up to 25mA, high-level output current up to 20mA. Compared with the 51 series, this is a great advantage.

　　3. It can directly drive the digital tube display and the external circuit is simple. Its A/D is 10 bits, which can meet the accuracy requirements. It has online debugging and programming (ISP) functions.

　　Disadvantages:

　　Its special registers (SFR) are not concentrated in a fixed address range (80~FFH) like the 51 series, but are scattered in four address ranges. Only 5 special registers PCL, STATUS, FSR, PCLATH, INTCON appear in 4 storage bodies at the same time, but in the programming process, it is inevitable to deal with special registers, and the corresponding storage body must be repeatedly selected, that is, the 6th bit (RP1) and the 5th bit (RP0) of the status register STATUS are set or cleared. Data transmission and logical operations are basically carried out through the working register W (equivalent to the accumulator A of the 51 series), and the 51 series can also be directly transmitted between registers. Therefore, the bottleneck phenomenon of PIC microcontrollers is more serious than that of the 51 series. Friends who are programming should have a deep understanding of this. [page]

　　The most commonly used devices: PIC16F873, PIC16F877.

　　AVR MCU

　　AVR microcontroller is a relatively new microcontroller launched by Atmel. Its notable features are high performance, high speed and low power consumption. It cancels the machine cycle, takes the clock cycle as the instruction cycle, and implements pipeline operation. AVR microcontroller instructions are in words, and most instructions are single-cycle instructions. A single cycle can execute the function of the current instruction and complete the reading of the next instruction at the same time. Usually the clock frequency is 4~8MHz, so the shortest instruction execution time is 250~125ns. AVR microcontroller can become a relatively popular microcontroller recently. Its main features are:

　　Features:

　　1. The AVR series does not have a structure similar to the accumulator A. It mainly uses registers R16~R31 to implement the function of A. In the AVR, there is no data pointer DPTR like the 51 series. Instead, the data pointer function is completed by three 16-bit registers X (composed of R26 and R27), Y (composed of R28 and R29), and Z (composed of R30 and R31) (equivalent to three groups of DPTR), and it can also perform post-increment or pre-decrement operations. In the 51 series, all logical operations must be performed in A; while the AVR can be performed between any two registers, eliminating the need to go back and forth in A. These are better than the 51 series.

　　2. AVR's dedicated registers are concentrated in the 00~3F address range. Unlike PIC, there is no need to select the storage bank first, which makes it more convenient to use. The address range of AVR's on-chip RAM is 0~00DF (AT90S2313) and 0060~025F (AT90S8515, AT90S8535). They occupy the address of the data space. These on-chip RAMs are only used to store data and usually do not have the function of general registers. When the program is complex, the general registers R0~R31 are not enough; the 51 series has up to 128 general registers (4 times that of AVR), so you won't feel this way when programming.

　　3. AVR's I/O pins are similar to PIC. It also has a direction register for controlling input or output. In the output state, the high-level output current is about 10mA, and the low-level sink current is 20mA. Although this is not as good as PIC, it is still better than the 51 series...

　　shortcoming:

　　1. There is no bit operation, and the relevant register bits are controlled and judged in byte form.

　　2. There are big differences in the writing methods between C language and 51's C language, which makes friends who are just starting to learn 51 microcontrollers very uncomfortable.

　　3. There are 32 general registers (R0~R31), and the first 16 registers (R0~R15) cannot directly deal with immediate values, so their versatility is reduced. In the 51 series, all its general registers (address 00~7FH) can directly deal with immediate values, which is obviously better than the former.

　　The most used devices: ATUC64L3U, ATxmega64A1U, AT90S8515.

　　STC MCU

　　When it comes to STC microcontrollers, some people will say that STC can also be considered mainstream, and I guess they will be criticized~~ We are talking about it based on the fact that it is a relatively good microcontroller in China. STC microcontrollers are single-clock/machine cycle microcontrollers produced by Hongjing. To put it bluntly, STC microcontrollers are a combination of 51 and AVR. Some people say that AVR is a replacement microcontroller for 51, but there are great differences in bit control and C language writing of AVR microcontrollers. The STC microcontroller combines the advantages of 51 and AVR. Although its functions are not as powerful as AVR, the functions found in AVR are basically available on STC. At the same time, the STC microcontroller is a 51 core, which provides great convenience for engineers who use 51 microcontrollers as the basis, saving the time of learning AVR, while not losing the various functions of AVR...

　　STC microcontroller is a new generation of 8051 microcontroller with high speed, low power consumption and strong anti-interference. The instruction code is fully compatible with the traditional 8051, but the speed is 8~12 times faster. It has an internal integrated MAX810 dedicated reset circuit. 4-channel PWM 8-channel high-speed 10-bit A, D conversion, for motor supplier control, strong interference occasions, becoming a new series of microcontrollers after 51 microcontrollers...

　　characteristic:

　　1. It is convenient and easy to use the serial port to download and burn programs. It is easy to use and has a large number of learning materials and videos. The most famous one is the video of Teacher Du. Many friends who are interested in microcontrollers get started through this video. It also has a wide voltage: 5.5~3.8V, 2.4~3.8V, low power consumption design: idle mode, power-down mode (can be awakened by external interrupt).

　　2. STC microcontrollers have the function of in-application programming and are easy to debug. They have 10-bit AD, internal EEPROM, and can operate at 1T/machine cycle. Their speed is 8 to 12 times that of traditional 51 microcontrollers, and they are also cheaper.

　　3. 4-channel capture/compare unit, STC12C2052AD series has 2 channels, which can also be used to realize 4 more timers or 4 external interrupts, 2 hardware 16-bit timers, compatible with ordinary 8051 timers. 4-way PCA can also realize 4 more timers, with hardware watchdog, high-speed SPI communication port, full-duplex asynchronous serial port, compatible with ordinary 8051 serial port, and also has advanced instruction set structure, compatible with ordinary 8051 instruction set.

　　PS:

　　Although the STC microcontroller is not as powerful as AVR and STM32, and its price is not as cheap as 51 and ST32, these are not important. What is important is that it is a relatively outstanding domestic microcontroller. I hope that domestic microcontrollers can continue to prosper...

　　The most used device: STC12C2052AD.

　　Freescale MCU

　　Mainly for S08, S12 and other MCUs, of course Freescale MCUs are far from that. Freescale series MCUs adopt Harvard structure and pipeline instruction structure, and they have shown low cost and high performance in many fields. Its architecture saves a lot of time for product development. In addition, Freescale provides a variety of integrated modules and bus interfaces, which can play a more flexible role in different systems! The unique features of Freescale MCUs are as follows:

　　1. Full range: From low-end to high-end, from 8-bit to 32-bit, the full range is available. The 8-bit/32-bit pin-compatible QE128 launched by it can be directly ported from 8-bit to 32-bit, making up for the missing link in the 8/32-bit compatible architecture of the MCU industry.

　　2. Multiple system clock modules: three modules, seven working modes. Multiple clock source input options, different MCUs have different clock generation mechanisms, which can be RC oscillators, external clocks or crystal oscillators, or internal clocks. Most CPUs have the above three modules at the same time! It can run in seven working modes: FEI, FEE, FBI, FBILP, FBE, FBELP, and STOP.

　　3. Multiple communication module interfaces: Freescale microcontrollers integrate almost all kinds of communication interface modules internally: including serial communication interface module SCI, multi-master I2C bus module, serial peripheral interface module SPI, MSCAN08 controller module, and universal serial bus module (USB/PS2).

　　4. It has more optional modules: LCD driver module, temperature sensor, UHF transmission module, synchronous processor module, MCU with synchronous processor also has screen display module OSD, and a few MCUs have ring detection module RING and dual-tone multi-frequency/tone generator DMG module.

　　5. High reliability, strong anti-interference, and a variety of pin counts and package options.

　　6. Low power consumption. The power consumption of Freescale series microcontrollers may not be as low as that of MSP430, but they have two fully static modes, "wait" and "stop", which can reduce your power consumption overall! Several recently launched ultra-low power consumption microcontrollers are comparable to MSP430!

　　Most used devices: MC9S12G series

　　If we really want to rank these microcontrollers, then if you want to follow the crowd, the 51 microcontroller is undoubtedly the first choice; if you pursue ultra-high cost performance, STM32 will be your ideal choice; if you desire ultra-low power consumption, MSP430 will definitely not let you down; if you want to support domestic products, STC will make you excited...

　　Which of these seven mainstream microcontrollers is the best? I believe you should know it now~~

　　Some friends will say that Renesas MCU has the largest sales volume, and is widely used in the automotive electronics industry , with good stability, but I personally don't like Japanese products, so I haven't used Renesas products. This varies from person to person, but it is undeniable that its large sales volume must have its merits, and I hope my colleagues understand this~~