Analysis of the advantages and disadvantages of several commonly used single-chip microcomputers

Several used MCU comparisons (personal views) are available for selection by reviewers and beginners.

51 series single chip microcomputer

There are many people using it, a lot of information, and no technical support at all. The price is cheap (such as the batch AT89c52 only needs 8.5RMB). However, ordinary chips have less internal resources and require external expansion. The bus externally makes the system anti-interference type worse. The external watchdog circuit increases the cost (max813 is more expensive than 89c52). The execution speed is slow, the crystal frequency is high, and the EMI performance is poor.

High power consumption, can not be used for low-power products (although philip has low-power products, but the price is not as good as pic microcontroller).

In recent years, there have been some 51 single-chip microcomputers with extended functions, such as external ram built-in, 2 uart, spi interface, a/d converter, etc. The price is not very expensive, but the batch size and product expect a long life cycle, and there are concerns about use. All of the above mentioned are all shortcomings, but the advantages of 51 single-chip microcomputer are also very obvious. 51 single-chip microcomputer is a relatively large resource in the low-end 8-bit single-chip microcomputer, which is convenient for constructing a larger system with lower cost. Than. According to several 51 single-chip microcomputers (common types) used, the performance of ATMEL and PHILIP is similar, but ATMEL is cheaper, Winbond has better performance, but the price is higher.

The development tools are medium in price and the development methods are backward. Because the program space is large, the stack can be moved, it is suitable for C programming, the compilation software is also good (keil), and the programmer (LABTOOL-48) supports it better.

The following microcontrollers are not used much.

Motorola's MCU (limited to my level, only talk about 8-bit MCU), less information (and mistakes, have their own lessons), not many people use, technical support in general, small customers are basically not supported. Used 908gp32, crystal oscillator is 32768Hz, internal PLL multipliers to 4MHz, better anti-interference, more resources, basically no expansion. But the price is higher, but the price of 908JL8 is better than 89c52, and there are many types, including almost all functions, but there seems to be no low-power products.

Simulation development tools are expensive (but because of the internal monitoring program, the 908 (flash) series can make simple debugging and downloading tools). The development method is more advanced. Applicable to C programming (experience is good even if you are not familiar with assembly language), the software development tool CodeWarrior is powerful, but it is somewhat different from other development tools. Oddly, some header files have errors. The high version of the programmer (LABTOOL-48) supports better.

Msp430 microcontroller. Technical support is also available, and there is not much information. Used F11x1, low power consumption and fast speed, assembly language is very flexible to use, there are many addressing methods, few instructions, easy to use. The disadvantage is that there are fewer on-chip resources, no a/d and sputum, but the slope a/d can be used (fear of interruption). The disadvantage is that the instruction space is large, because it is a 16-bit microcontroller, the program is in words, and some instructions actually occupy 6 bytes. Although the program is succinct on the surface, the space is very large (compared to the pic microcontroller). There is a flash information storage inside, which is used to save the information without power down, and is generally used. Must be paged, data must be read back to write, the same as the flash operation, read simple write trouble. The low-end type of Msp430 microcontroller is not as good as pic microcontroller. The reset characteristics are poor. According to the actual application, when the power-down voltage drops slowly, the instantaneous power-down reset performance is poor, and a reset chip is required.

Compared with other microcontrollers, simulation development is the most convenient one. Jatg interface, you can quickly download the program to the flash storage, and then the debugging function is OK, the debugging tools are cheap, and the software development tool IAR is also quite good. The programmer (LABTOOL-48) does not support it.

Best for getting started.

Pic microcontroller, technical support is good (I don't know how to attitude towards small customers), is the popular microcontroller after 51.

Although the hardware structure and language are strange, the development methods are backward. But the price is cheap, the power consumption is low (but the frequency is low enough), and it is very practical. The program code space is very economical and is related to its structure. If you use other microcontrollers and switch to pic, you will feel awkward. Because the stack pointer is immutable, it is not applicable to the C language (the ram definition of the c language should also be paged, it should be the first one), assembly language is OK. The most practical resource of the Pic microcontroller is the a/d converter (and cheaper than the a/d alone). The IIC interface is basically useless (because it is more troublesome to use than the soft copy), the serial port is also general, such as no multi-machine communication function. (except for high grade), although there are many interruptions, there is only one entrance.

Some have an internal EEROM, but still an IIC interface, some are called parallel interfaces, but not in the ram space, reading and writing is still troublesome. Pic microcontroller hardware features are better, consider very thoughtful, such as good reset performance (delay power-on reset, power-on reset, power-down reset), watchdog is also good, and anti-interference is good, in many applications do not need to add Auxiliary circuits are especially suitable for low cost applications.

The simulation development tool (ice2000) is expensive, and it is necessary to replace the simulation module with a unit price of several thousand yuan depending on the microcontroller. Of course, you can use domestic. I recently introduced an ICD2, but downloaded the monitor to the on-chip program space and took up the ram. It is not very practical for chips with few resources.