89S51 single chip microcomputer (transferred)

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89S51 single chip microcomputer (transferred) [Copy link]

Many netizens who are new to 51 MCUs have this question: What is AT89S51? Books and online tutorials all mention 8051, 89C51, etc.! Have you ever heard of 89S51? !　
　　Here, beginners need to clarify a product concept in the actual use of MCUs. MCS-51 MCUs are products launched by INTE Corporation of the United States in 1980. Typical products include 8031 (no internal program memory, which has been eliminated by the market in actual use), 8051 (the chip uses HMOS, the power consumption is 630mW, which is 5 times that of 89C51, which has been eliminated by the market in actual use) and 8751 and other general products. Until now, MCUs compatible with the MCS-51 core series are still the mainstream products used (such as the currently popular 89S51, 89C51, etc.). The training materials of various universities and professional schools still use MCS-51 MCUs as representatives for theoretical basic learning.
　　Some documents even refer to 8051 as the MCS-51 series of microcontrollers. 8051 is the most typical representative work in the early days. Due to the far-reaching influence of MCS-51 microcontrollers, many companies have launched compatible series of microcontrollers, which means that the MCS-51 core has actually become a standard for 8-bit microcontrollers.
　　The 51 microcontroller products of other companies are all compatible with the MCS-51 core. The same program will have the same results when running on the hardware of various microcontroller manufacturers, such as ATMEL's 89C51 (discontinued), 89S51, PHILIPS, and WINBOND. The discontinued 89C51 we often refer to ATMEL's AT89C51 microcontroller, which has enhanced many features on the original basis, such as the clock. What's more, the original ROM (one-time write) is taken from the Flash (the contents of the program memory can be rewritten at least 1,000 times) memory. The performance of AT89C51 is already very superior to 8051.
　　However, in terms of marketization, 89C51 has been challenged by the PIC microcontroller camp. The most fatal flaw of 89C51 is that it does not support the ISP (online update program) function. New functions such as ISP function must be added to better continue the legend of MCS-51. 89S51 replaced 89C51 in this context. Now, 89S51 has become the new darling in the actual application market. Atmel, which has the largest market share, has stopped producing AT89C51 and will replace it with AT89S51. 89S51 has been improved in process. 89S51 adopts 0.35 new process, which reduces cost and improves function, increasing competitiveness. 89SXX can be compatible with 89CXX and other 51 series chips. At the same time, Atmel no longer accepts orders for 89CXX. The 89C51 that everyone sees in the market is actually the huge inventory produced by Atmel in the early stage. If the market needs it, Atmel can of course resume production of AT89C51.

The new features added by 89S51 compared with 89C51 include:

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

-- ISP online programming function. The advantage of this function is that the program in the microcontroller memory does not need to be removed from the working environment. It is a powerful and easy-to-use function.

-- The maximum operating frequency is 33MHz. As we all know, the maximum operating frequency of 89C51 is 24M, which means that S51 has a higher operating frequency and thus has a faster computing speed.

-- It has a duplex UART serial channel.

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

-- Dual data indicator.

-- Power off mark.

-- Brand-new encryption algorithm, which makes it impossible to decrypt 89S51, and the confidentiality of the program is greatly enhanced, so that intellectual property rights can be effectively protected from infringement.

-- Compatibility: fully compatible with all 51-word series products. For example, 8051, 89C51 and other early MCS-51 compatible products. That is to say, all the programs in textbooks and online tutorials (regardless of whether the microcontroller used in the textbook is 8051, 89C51, MCS-51, etc.) can run normally on 89S51. This is the so-called backward compatibility.

　　Comparison results: Just like the upgrade from INTEL's P3 to P4, although both can run Windows 98, the speed is different. The upgrade from AT89C51 to AT89S51 is the same. Compared with S51, C51 is inferior, and the progress of technology in the actual application market is always moving forward.

********The above is the origin of AT89S51********　
　
　　The following are the common questions asked by beginner netizens about the selection of 51 series

1 Question: Common questions asked by netizens: Should I choose AT89C51 or 89S51 when studying 51 series microcontrollers?
Answer: 89C51 and 89S51 have the same core. 89S51 has several obvious upgrades over 89C51 as follows;　
1. Program memory writing method: The two have different ways of writing programs. 89C51 only supports parallel writing and requires VPP to burn high voltage. 89S51 supports ISP online programmable writing technology! Serial writing, faster speed, better stability, and the burning voltage only needs 4~5V.
2. Power supply range: 89S5* has a wide power supply range of 4~5.5V, while the 89C5* series cannot work properly when it is lower than 4.8V and higher than 5.3V.
3. Operating frequency: At present, the performance of 89S1* is much higher than that of 89C5*. The 89S5* series supports an operating frequency of up to 33MHZ, while the 89C51 operating frequency range only supports up to 24M.
4. Market price: Since 89C51 has been completely discontinued, the wholesale price of 89C5* in stock is nearly twice as expensive as 89S5* in terms of market price!
5. Compatibility: 89S5* is backward compatible with 89C5*, which means that 89S5* can replace 89C5*, and the same program has the same running results. That is to say, 89S5* is also compatible with all current textbook example programs.
6. Encryption function: 89S5* series has a brand new encryption algorithm, which makes it impossible to decrypt 89S51, and the confidentiality of the program is greatly enhanced, so that intellectual property rights can be effectively protected from infringement.
7. Anti-interference: The internal integrated watchdog timer no longer needs an external watchdog timer unit circuit like 89C51.
8. Longer burning life: 89S5* nominal 1000 times, the actual minimum is 1000 to 10000 times, which is more conducive to repeated burning for beginners and reduces learning costs. Based on the above differences, I personally think that it is only a matter of time before 89C51 is discontinued, just like 8031 in the past.

2Q: Is it better to use 89C2051 to develop and manufacture products than 89S51? Because 2051 looks smaller.
A: This question cannot be generalized. The main differences are as follows:
1. Functional difference: Because 2051 is not a standard 51 core, 205* programs cannot be directly ported to 51. Since 205* is a streamlined type, there are very few P ports, so it can only be used to make some small and simple products, and the available resources are relatively tight. In fact, it is not necessarily cost-effective to use 205* to make products, unless it is a very simple product.
2. Market price: Since the output of 89C2051 is not very large, the wholesale price of 89C2051 is close to that of 89S51! The relative performance-price ratio is relatively low. 3.
Product volume: Unless there are strict requirements on the volume of the product, the PCB area of the two is not much different, because the 40-pin 51 chip also has a PLCC44 small package.

KZ610

Cheap 51 MCU, needs more AD pins, please recommend 6, 8, 10, 14, 16, 20PIN