What Is a Series 51?

51 microcontroller is a collective name for all microcontrollers compatible with the Intel 8031 instruction system. The ancestor of this series of microcontrollers is Intel's 8004 microcontroller. Later, with the development of Flash rom technology, 8004 microcontrollers have made great progress and become one of the most widely used 8-bit microcontrollers. Widely used in industrial measurement and control systems. Many companies have launched 51 series compatible models, which will occupy a large number of markets for a long time to come. 51 single-chip microcomputer is a basic one-chip computer, or one of the most widely used. It should be noted that 51 series microcontrollers generally do not have self-programming capabilities.

51 SCM

51 MCU is compatible with all Intel 8031

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As a beginner, how to start a microcontroller?

The same program runs on the hardware of each microcontroller manufacturer. The results are the same, such as ATMEL 89C51 (discontinued), 89S51, PHILIPS, and WINBOND. AT89C51 single-chip microcomputer, at the same time enhanced many features on the original basis, such as the clock, the better is the Flash (program memory content can be rewritten at least 1000 times) memory replaced the original ROM (write-once), AT89C51 performance Compared to 8051 is already very superior.

However, in terms of marketization, the 89C51 has been challenged by the PIC microcontroller camp. The most fatal flaw of the 89C51 is that it does not support ISP (Online Update Program) functions. New features such as ISP functions must be added to continue the MCS-51 legend. 89S51 replaced 89C51 under this background. 89S51 has become the new darling in the actual application market. Atmel, the market share leader, has stopped production of AT89C51 and will use AT89S51 instead. The 89S51 has been improved in technology. The 89S51 uses a new 0.35 process, which reduces costs, improves functions, and increases competitiveness. 89SXX is backward compatible with 51 series chips such as 89CXX. At the same time, Atmel no longer accepts 89CXX orders. The 89C51 you see on the market is actually a huge inventory of Atmel's previous production. If the market requires, Atmel can of course resume production of AT89C51.

Compared with 89C51, the new functions of 89S51 include:

-Many new functions have been added, the performance has been greatly improved, and the price is basically unchanged, even lower than 89C51!

-ISP online programming function. The advantage of this function is that rewriting the program in the memory of the microcontroller does not need to strip the chip from the working environment. Is a powerful and easy-to-use feature.

-The maximum operating frequency is 33MHz. Everyone knows that the limit operating frequency of the 89C51 is 24M, which means that the S51 has a higher operating frequency and thus has a faster calculation speed.

-Has a duplex UART serial channel.

-Internal watchdog timer integrated, no longer need external watchdog timer unit circuit like 89C51.

-Dual data indicator.

-Power off indicator.

-A new encryption algorithm, which makes it impossible to pirate 89S51, and the confidentiality of the program is greatly strengthened, so that intellectual property can be effectively protected from being infringed.

-Compatibility: Fully compatible with all 51 series products. For example 8051, 89C51, etc. Early MCS-51 compatible products. That is to say, all the programs on textbooks and network tutorials (regardless of whether the microcontroller used in the textbook is 8051, 89C51, MCS-51, etc.) can still run as usual on 89S51, which is called backward compatibility.

Comparison result: Just like INTEL's P3 to P4 upgrade, although they can run Windows98, the speed is different. The upgrade from AT89C51 to AT89S51 is the same. Compared with the S51, the C51 will be inferior, and the technological progress in the practical application market will always move forward.