Basic composition and selection of single chip microcomputer
公開時間: 2020-09-23 17:50:47
The basic composition of single chip
The full name of microcontroller is microcontroller, abbreviated as SCM.
MCU consists of processor, memory, interrupt/timer, and basic input and output circuits. MCU does not have as powerful digital peripherals as ARM CORTEX-M series microcontrollers. MCUs only have some simple timers, interrupts, serial ports, basic input and output circuits, and other peripheral devices, so they do not have strong electrical processing capabilities, and most of them need to expand peripheral devices.
The single-chip microcomputer generally adopts the improved Harvard architecture with independent instruction memory and data memory, while the traditional computer adopts the von Neumann architecture, with instructions and data in one memory. Since modern computers use cache technology with instruction cache and data cache, but still only have one memory, from the inside of the processor, it is an improved Harvard architecture, and from the outside, it is the von Neumann architecture. The computer is well integrated between the two architectures.
SCM programming usually uses C language, while assembly language is rarely used. It is mainly used for startup, on-site protection and recovery of RTOS and some places with strict time requirements. The SCM program architecture has a sequential execution structure based on front-end and back-end, time slice execution structure and RTOS structure. In programming, it is very important to master the software timer programming method based on time base.
Selection of MCU Chip
As the core component of the embedded microcontroller, how to choose the appropriate microcontroller is directly related to the success or failure of the embedded project development. Today I will talk to you about how to select the microcontroller in embedded development?
1. Manufacturer selection
Choose well-known manufacturers, the quality is guaranteed, and the information is relatively complete.
2. Stable and mature products
Try to choose a more mature single-chip microcomputer to develop the project. Do not choose some unstable single-chip microcomputers that have just been listed. It is easy to cause the project to fail due to the single-chip microcomputer.
3. Resource selection
Whether the internal resources of the microcontroller, including IO, Flash, etc. can meet the requirements of our project, try not to rely on external expansion to achieve some functions, so that the more devices, the more likely to have problems.
4. Is the tool easy to use
It is necessary to choose a programming tool, a single-chip microcomputer with a better simulation tool, which can increase the development speed.
5. Delivery cycle time
Before choosing a single-chip microcomputer, it is also necessary to ask how long the supply cycle is, the minimum supply quantity, and it will be difficult to bring the product to the market in time if it is not developed well.
6. Cost performance
On the basis of being able to meet the project development, choose a cost-effective single-chip.