The differences and characteristics of MCU, ARM, FPGA and embedded

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The differences and characteristics of MCU, ARM, FPGA and embedded [Copy link]

Features of single-chip microcomputers: (1) Limited by the integration level, the on-chip memory capacity is relatively small, generally ROM: less than 8KB; (2) RAM: less than 256KB. (3) High reliability (4) Easy to expand (5) Strong control function (6) Easy to develop Features of ARM: (1) It comes with cheap program memory (FLASH) and non-volatile data memory (EEPROM). These memories can be electrically erased and rewritten many times, making program development experiments more convenient and working more reliable. (2) High speed and low power consumption. Under the same crystal oscillator conditions as the M51 single-chip microcomputer, the operating speed of the AVR single-chip microcomputer is 30-40 times that of the M51 single-chip microcomputer; and the addition of sleep function and CMOS technology makes its power consumption much lower than that of the M51 single-chip microcomputer. (3) Industrial-grade products. It has a large current output that can directly drive SSR and relays, and has a watchdog timer to prevent the program from running away, thereby improving the product's anti-interference ability. (4) Super-functional streamlined instructions, with 32 general working registers, equivalent to 32 accumulators in the M51 single-chip microcomputer! Thus, the bottleneck effect of single accumulator operation is overcome. (5) Easy program download. AVR microcontrollers can be downloaded in parallel or serially, without the need for expensive programmers. In addition, they can be downloaded online! In other words, the program can be modified and burned directly on the circuit board. (6) It has analog comparator, pulse width modulator, and analog-to-digital conversion functions. This makes analog signal processing in industrial control simpler and more convenient. (7) The functions of important internal resources of the microcontroller, such as parallel port, timer counter, interrupt system, etc., have been greatly improved, making it more suitable for real-time control of industrial production processes. (8) Its clock frequency can be connected externally or use the oscillator built into the microcontroller. Its frequency can be set within 1MHz-8MHz, making hardware development and production simpler. (9) Powerful communication function, built-in synchronous serial interface SPI, universal serial interface UAST, two-wire serial bus interface TWI (I2C), making network control and data transmission more convenient. (10) Super confidentiality function, the application program can use multiple protection lock functions. It can quickly complete the commercialization of manufacturers' products at a low price, etc. In addition to the above features, "zero peripherals" is also an important feature of AVR embedded microcontrollers. Since the chip has built-in program memory, crystal oscillator and added online assembly function. Therefore, the AVR microcontroller chip can work independently by connecting it to a DC power supply and downloading a program. No additional external equipment is required, and no expensive programmers and simulators are required. This brings convenience to our learning and development. Features of FPGA: (1) FPGA is used to design ASIC circuits (application-specific integrated circuits), and users can get suitable chips without having to invest in production. (2) FPGA can be used as a pilot chip for other fully customized or semi-customized ASIC circuits. (3) FPGA has a rich set of triggers and I/O pins. (4) FPGA is one of the devices with the shortest design cycle, lowest development cost and lowest risk in ASIC circuits. (5) FPGA uses high-speed CMOS technology, low power consumption, and is compatible with CMOS and TTL levels. It can be said that FPGA chips are one of the best choices for small-batch systems to improve system integration and reliability. FPGA uses a program stored in the on-chip RAM to set its working state. Therefore, the on-chip RAM needs to be programmed when working. Users can use different programming methods according to different configuration modes. When powered on, the FPGA chip reads the data in the EPROM into the on-chip programming RAM. After the configuration is completed, the FPGA enters the working state. After power failure, the FPGA returns to a blank chip, and the internal logical relationship disappears. Therefore, the FPGA can be used repeatedly. FPGA programming does not require a dedicated FPGA programmer, but only a general EPROM or PROM programmer. When the FPGA function needs to be modified, just replace an EPROM. In this way, the same FPGA with different programming data can produce different circuit functions. Therefore, the use of FPGA is very flexible. Characteristics of embedded systems 1. Small system kernel Since embedded systems are generally used in small electronic devices and system resources are relatively limited, the kernel is much smaller than that of traditional operating systems. For example, the OSE distributed system of Enea has a kernel of only 5K, while the kernel of Windows? There is simply no comparison. 2. Strong specialization The embedded system is highly personalized, and the software system and hardware are closely integrated. Generally, the system needs to be transplanted for the hardware. Even in the same brand and the same series of products, it is necessary to continuously modify according to the changes and additions and subtractions of the system hardware. At the same time, for different tasks, it is often necessary to make major changes to the system. The compilation and download of the program must be combined with the system. This modification is completely different from the "upgrade" of general software. 3. System Streamlining Embedded systems generally do not have a clear distinction between system software and application software, and do not require their functional design and implementation to be too complicated. This is beneficial to control system costs on the one hand, and also beneficial to 4. High real-time system software (OS) is a basic requirement for embedded software. In addition, the software requires solid-state storage to increase speed; the software code requires high quality and high reliability. 5. If embedded software development is to move towards standardization, it must use a multi-tasking operating system. The application program of the embedded system can run directly on the chip without an operating system; however, in order to reasonably schedule multiple tasks, utilize system resources, system functions, and interface with expert library functions, users must select the RTOS (Real-Time Operating System) development platform by themselves, so as to ensure the real-time and reliability of program execution, reduce development time, and ensure software quality. 6. Embedded system development requires development tools and environment. Since it does not have the ability to bootstrap development, users usually cannot modify the program functions even after the design is completed. A set of development tools and environments are required for development. These tools and environments are generally based on software and hardware devices on general-purpose computers and various logic analyzers, mixed signal oscilloscopes, etc. During development, there are often concepts of host and target machines. The host is used for program development, and the target machine is the final execution machine. Development needs to be carried out alternately.