Classification by Purpose:
General-Purpose: The available resources (ROM, RAM, I/O, EPROM) are all available to the user.
Special type: Its hardware and instructions are designed for a specific purpose, such as a tape recorder movement controller, a printer controller, a motor controller, etc.
Number of data bits processed by their basic operations:
According to the width of bus or data registers, MCU is divided into 1-bit, 4-bit, 8-bit, 16-bit, 32-bit or even 64-bit microcontroller. Most of the 4-bit MCU is used in calculators, vehicle instrumentation, car anti-theft devices, pagers, cordless telephones, CD players, LCD drive controllers, LCD game consoles, children's toys, scales, chargers, tire pressure gauges, temperature hygrometer, remote control and shoot, and so on; most of the 8-bit MCU is used in electric meters, motor controllers, Electric Toy Machine, inverter-type air-conditioners, pagers, fax machines, caller ID (callerid), telephone recorders, CRT monitors, keyboards and USB, etc. 8-bit, 16-bit microcontroller is mainly used in general control areas, generally do not use the operating system, 16 MCU most applications in mobile phones, Digital cameras and video camera, and so on; most of the 32-bit MCU is used in modem, GPS, PDA, HPC, STB, Hub, Bridge, Router, workstation, ISDN telephone, laser printer and color fax machine, 32 bits for network operation, multimedia processing and other complex processing occasions , the embedded operating system is generally used. Most of the 64-bit MCU is used in higher-order workstations, multimedia interactive systems, advanced TV rides (such as Sega Dreamcast and Nintendo Gameboy) and advanced terminals.
8-bit MCU operating frequency between 16~50mhz, emphasizing simple efficiency, low-cost applications, in the current MCU market value still has a certain position, and a number of MCU has continued to 8bit MCU development frequency regulation of energy-saving design, in response to the green era of product development needs.
16-bit MCU, then 16-bit operations, 16/24-bit addressing capacity and frequency in the 24~100mhz for the mainstream specifications, some 16bit MCU additional 32 plus/minus/multiply/divide special instructions. Because the 32bit MCU appears and continue to reduce prices and 8bit MCU simple and durable and inexpensive low-cost advantage, sandwiched in the middle of the 16bit MCU market has been squeezed, to become the lowest proportion of products shipped.
32 MCU can be said to be the mainstream MCU market, single quotation in 1.5~4 between the United States dollar, the frequency of work is mostly between the 100~350mhz, the implementation efficiency is better, the application type is also quite many yuan. However, 32-bit MCU will be due to the increase in the number of operands and memory length, the same function of the program code length than the 8/16bit MCU to increase $number, which results in embedded otp/flashrom memory capacity can not be too small, and chip external to the number of feet increased, further limited to 32bit MCU cost reduction capability.