51, Comparison of PIC and AVR microcontrollers

        I don't think I will say much about the traditional 51. It is suitable for beginners, easy to use, and the price is average (in terms of cost performance).
        Disadvantages: easy to decrypt (the traditional 51 says: who let us debut early, everyone is studying me, hey! Cry...) It also has general functions, but functions such as AD and eeprom need to be expanded, which increases the burden on hardware and software.
        The IDE environment recommended is keil.

        2. PIC
        The advantage of PIC is that the various models are highly compatible. Once you have learned PIC16f877a, the 16 series will be OK. When you need to use other models, just take 2 minutes to read the data sheet. The 12 series, 16 series, and 18 series are also fully backward compatible. Full functions, many models, suitable for selection analysis, strong anti-interference ability
        Disadvantages: easy to decrypt (pic said: I debuted very early, and people have been studying me for a long time. O'Neal and I are heroes!), the price of the microcontroller is expensive (in terms of cost performance).
        IDE environment: picc+mplab is recommended

        3. AVR Mega Series
        AVR Mega Series: The price is relatively cheap (in terms of cost performance), the hardware structure is suitable for C language programming, the functions are complete, and it is not easy to decrypt. The anti-interference ability is strong. The compatibility between models is average. It should be said that it is a relatively satisfactory piece.
        Disadvantages: There are many function registers, which is not suitable for beginners. With personal efforts, this disadvantage is not a disadvantage. Come on, everyone!
        IDE environment: CVAVR+Studio In fact, icc and gcc are also good. You can decide for yourself, haha.

        4. STC 51 series
        STC 51 series, I learned this microcontroller for the first time. It is cheap, cost-effective, has many functions, has the strongest anti-interference ability, has a large eeprom, and is very convenient for serial port programming (whether for beginners or product development and debugging). The program boot area is encrypted when it leaves the factory, and the market price of STC decryption is between 1.5w and 2.5w. It can be seen that the decryption is difficult, which protects the interests of microcontroller engineers and product developers to a certain extent. The compatibility with the traditional 51 has been considered during production, and the compatibility is very good. Many functions have been added, and I like the soft reset function.
        Disadvantages: The information is the information on the website of the product company (Hongjing), which is less and not suitable for beginners---I mean learning the functions it adds. (This disadvantage is not a disadvantage. The information of the product company is also very detailed, but I can't say that STC has no disadvantages. Other microcontrollers have them. If I say that STC has no disadvantages or doesn't say it, it would be too biased, haha)
        IDE: keil.
        Header file: Available on the product company website, you can use at89x52.h, define the new registers yourself or write a header file yourself.
         Summary:
        Each microcontroller has its own advantages and disadvantages. You can choose the application chip that suits your application based on your familiarity. For developers, make specific choices based on the specific needs of the project.
        For beginners, it is recommended that you use the stc 51 series microcontroller. The stc 51 series microcontroller is a very good choice

Common chip analysis
HT: The tool is easy to use. DEMO is difficult to make. The cost is medium.

PIC: The tool is difficult to use, but the DEMO is easy to make. The cost is relatively high.

FREESCALE: The tool is difficult to use, but the demo is easy to make. The cost is relatively high.

STC/51: The tool is easy to use, and the DEMO is easy to do. The cost is relatively low.

AVR: Easy to use tools, easy to make DEMO. Medium cost.

MSP430: The tool is very easy to use and the DEMO is easy to do. The cost is relatively high.

EMC: The tool is easy to use, but the demo is difficult to make. The cost is relatively low.

SUNPLUS: The tool is difficult to use and the DEMO is difficult to make. The cost is low.

TENX: The tool is difficult to use and the DEMO is difficult to make. The cost is low.

OKI: The tool is hard to use, and the demo is hard to get. The cost is low.

EPSON: The tool is difficult to use, but the DEMO is easy to make. The cost is relatively low.

PHILIPS: The tool is easy to use and the DEMO is easy to make. The cost is relatively high.

WINBOND: The tool is easy to use, and the DEMO is easy to make. The cost is medium. Next, I will introduce several commonly used single-chip microcomputer chips in China:

PIC microcontroller:
        It is a product of MICROCHIP. Its outstanding features are small size, low power consumption, streamlined instruction set, good anti-interference, high reliability, strong analog interface, good code confidentiality, and most chips have compatible FLASH program memory chips.

EMC microcontroller:
        It is a product of Taiwan Elan Corporation. A large part of it is compatible with PIC 8-bit microcontrollers. The resources of compatible products are relatively more than PIC, the price is cheap, and there are many series to choose from, but the anti-interference is poor.

ATMEL MCU (51 MCU):
        ATMEIL's 8-bit MCU has two series: AT89 and AT90. The AT89 series is an 8-bit Flash MCU, compatible with the 8051 series MCU, with a static clock mode; the AT90 series MCU is an enhanced RISC structure, fully static working mode, and built-in online programmable Flash MCU, also called AVR MCU.

PHLIPIS 51PLC series microcontroller (51 microcontroller):
        PHILIPS's microcontroller is based on the 80C51 core, embedded with power-off detection, simulation, and on-chip RC oscillator functions, which enables 51LPC to meet various performance requirements in high-integration, low-cost, and low-power application designs.

HOLTEK MCU:
        Taiwan Shengyang Semiconductor's MCU, cheap, more types, but poor anti-interference, suitable for consumer products.

TI Microcontroller (51 MCU):
        Texas Instruments provides two series of general-purpose MCUs: TMS370 and MSP430. The TMS370 series MCU is an 8-bit CMOS MCU with multiple storage modes and multiple peripheral interface modes, suitable for complex real-time control occasions; the MSP430 series MCU is an ultra-low power, high-functionality 16-bit low-power MCU, especially suitable for occasions requiring low power consumption. 
 

Next, let's talk about the single-chip microcomputer chip products of International Electronics:
1. MOTOROLA single-chip microcomputer      
MOTOROLA is the world's largest single-chip microcomputer manufacturer. Its characteristics are a full range of varieties, a wide range of choices, and many new products. In terms of 8-bit machines, there are 68HC05 and production-level products 68HC08. 68HC05 has more than 30 series and more than 200 varieties, and the output has exceeded 2 billion pieces. There are also more than 30 varieties of 8-bit enhanced single-chip microcomputer 68HC11, and the annual output is more than 100 million pieces. Production-level products include 68HC12. There are also more than ten varieties of 16-bit machines 68HC16. There are also dozens of varieties of 32-bit single-chip microcomputer 683XX series. In recent years, single-chip microcomputers with PowerPC, Coldfire, M.CORE, etc. as CPUs and DSP integrated as auxiliary modules have also been launched one after another, and they are still the first choice of single-chip microcomputers. One of the characteristics of MOTOROLA microcontrollers is that the clock frequency used is much lower than that of Intel-type microcontrollers at the same speed, which makes the high-frequency noise low and the anti-interference ability strong, making it more suitable for industrial control fields and harsh environments. In the past, the strategy of MOTOROLA 8-bit microcontrollers was mainly based on masks. Recently, the OTP plan was launched to adapt to the development trend of microcontrollers. On 32-bit machines, M.CORE outperforms ARM7 in terms of performance and power consumption.    
2. Microchip microcontrollers      
Microchip microcontrollers are the microcontrollers with the fastest market share growth. Its main products are 16C series 8-bit microcontrollers. The CPU adopts RISC structure, has only 33 instructions, runs fast, and is known for its low price. The general price of microcontrollers is less than one dollar. Microchip microcontrollers do not have mask products, all of which are OTP devices (FLASH microcontrollers have been launched in recent years - Editor's note). Microchip emphasizes cost-saving optimization design, and uses large-volume, low-grade, and price-sensitive products.      
3. Scenix microcontrollers      
The I/O module of Scenix microcontrollers is innovative. The integration and combination technology of I/O modules is an important and indispensable aspect of single-chip microcomputer technology. In addition to traditional I/O function modules such as parallel I/O, URT, SPI, I2C, A/D, PWM, PLL, DTMF, etc., new I/O modules continue to emerge, such as USB, CAN, J1850, the most representative of which is the MOTOROLA 32-bit single-chip microcomputer, which integrates I/O modules including various communication protocols, and the Scenix single-chip microcomputer introduces the new concept of virtual I/O in the processing of I/O modules. Scenix uses a RISC structure CPU, which makes the CPU's maximum operating frequency reach 50MHz. The computing speed is close to 50MIPS. With a powerful CPU, various I/O functions can be simulated by software. The package of the single-chip microcomputer uses 20/28 pins. The company provides various I/O library functions to realize the functions of various I/O modules. These modules completed by software include multi-channel UART, multiple A/D, PWM, SPI, DTMF, FSK, LCD driver, etc. These are modules that are usually quite complex to implement in hardware.    
4. NEC MCU      
NEC MCU is a self-contained system, with the highest output of 8-bit MCU 78K series, and also 16-bit and 32-bit MCU. MCUs above 16 bits use internal frequency multiplication technology to reduce the external clock frequency. Some MCUs use built-in operating systems. NEC's sales strategy focuses on serving major customers, and invests considerable technical resources to help major customers develop products.      
5. Toshiba MCU      
Toshiba MCU features a full range of 4-bit to 64-bit machines. 4-bit machines still have a large market in the field of home appliances. 8-bit machines mainly include 870 series, 90 series, etc. This type of MCU allows the use of slow mode, and the power consumption is as low as 10uA when using 32K clock. The use of multiple groups of registers inside the CPU makes interrupt response and processing faster. Toshiba's 32-bit MCU uses the CPU structure of MIPS3000ARISC, targeting the VCD, digital camera, image processing and other markets.      
6. Fujitsu MCU      
Fujitsu also has 8-bit, 16-bit and 32-bit MCUs, but the 8-bit MCU uses the CPU core of the 16-bit MCU. That is to say, the instructions used by the 8-bit MCU and the 16-bit MCU are the same, making development easier. The 8-bit MCU has the famous MB8900 series, and the 16-bit MCU has the MB90 series. Fujitsu focuses on serving large companies and large customers and helping them develop products.    
7. Epson MCU    
Epson is well known for its expertise in manufacturing liquid crystal displays, so Epson MCUs are mainly used for LCDs produced by the company. The characteristic of its MCU is that the LCD driver part is particularly good. It is also very distinctive in terms of low voltage and low power consumption. At present, 0.9V powered MCUs have been launched on the market. In the near future, LCD display watch MCUs will use 0.5V power supply.      
8. 8051 MCU      
The 8051/31 type MCU first launched by Intel is also one of the most widely used MCUs in the world. Since Intel has focused on the development of high-end chips such as 186, 386, and Pentium that are compatible with PCs in terms of embedded applications, the 8051 microcontrollers are mainly produced by Philips, Samsung, Winbond and other companies. These companies have improved many features of the 8051 (such as timing characteristics) while maintaining compatibility with the 8051 microcontroller. The speed has been increased, the clock frequency has been reduced, the dynamic range of the power supply voltage has been widened, and the price of the product has been reduced.      
8. Zilog Microcontroller      
The Z8 microcontroller is a product of Zilog, which uses a multi-accumulator structure and has strong interrupt processing capabilities. The product is an OTP type, and the development tools of the Z8 microcontroller are inexpensive and good quality. The Z8 microcontroller is aimed at low-end applications with its low price advantage, mainly in 18-pin packaging, and the ROM is 0.5-2k. Recently, Zilog has launched the Z86 series of microcontrollers, which can integrate cheap DSP units.      
9. NS MCU      
COP8 MCU is a product of National Semiconductor Corporation, which is famous for producing advanced analog circuits and can produce high-level digital analog hybrid circuits. COP8 MCU integrates 16-bit A/D, which is rare in MCU. COP8 MCU uses anti-EMI circuit inside, and has unique features in watchdog circuit and wake-up method of MCU in STOP mode. In addition, COP8's program encryption control is also done very well.      
10. Samsung MCU      
Samsung MCU includes KS51 and KS57 series 4-bit MCU, KS86 and KS88 series 8-bit MCU, KS17 series 16-bit MCU and KS32 series 32-bit MCU. Samsung MCU has OTP type ISP on-chip programming function. Samsung is famous for producing memory chips. In the form of oversupply in the memory market, it has been involved in the competition of MCU. Samsung introduced and digested the technology of developed countries in single-chip microcomputer technology, produced products compatible with it, and then won with price advantage. For example, it adopted NEC technology for 4-bit machines, introduced Zilog Z8 technology for 8-bit machines, purchased ARM7 core for 32-bit machines, and also DEC technology and Toshiba technology. The price of its single-chip microcomputer bare chip is quite competitive.      
11. Winbond single-chip microcomputer      
Winbond MCU belongs to the 8051 type MCU. Their W78 series is compatible with the standard 8051, and the W77 series is an enhanced 51 series, which improves the timing of the 8051. The speed is increased by 2.5 times at the same clock frequency, and the FLASH capacity is increased from 4k to 64k, with ISP function. In terms of 4-bit MCUs, Winbond has the 921 series and the 741 series with LCD driver. In terms of 32-bit machines, Winbond uses HP's PA-RISC MCU technology to produce low-bit 32-bit RISC MCUs.

It's OK for everyone to understand this knowledge. As for which one to use, I personally feel that 51 is the most used. You can choose it yourself. . .