Summary of various common peripherals in embedded systems

技术小白521

Summary of various common peripherals in embedded systems [Copy link]

Background In embedded systems, there are many common peripherals in hardware. Here, we will sort them out. What are peripherals in embedded systems? Peripherals == External devices == Peripheral · External: Mainly refers to the peripherals other than the main CPU in the embedded system, i.e. SoC, MCU, etc. · Device: A certain hardware functional module Peripheral == Interface Here, the peripherals referred to are also often called various interfaces, hardware interfaces. Because: there are corresponding physical visible ones, as well as those that are not easy to see by the naked eye inside the hardware, and various interfaces are connected to external devices through corresponding interfaces. Let's summarize the common peripherals. Various common peripherals in embedded systems AFE (Analog Front End) A module that contains a bunch of analog circuits to implement corresponding analog functions. For example, amplifiers, filters, etc. It is often related to data acquisition, audio, etc. ADC/DAC Analog Digital Converter/ Digital Analog Converter Analog-to-digital converter/ Digital-to-analog converter converts between analog and digital. For example: ADC is often used to plug in a certain sensor, and then converted into corresponding digital signals through ADC or DAC, and then the corresponding data can be read through the embedded SoC. CRC hardware module Of course, the CRC algorithm can be implemented by software. However, in order to improve the efficiency of the calculation, sometimes you can use the existing CRC module to implement the CRC calculation. For example: Using the CRC Module on the Flexis AC Family CRC itself has some detailed divisions and names such as: CRC16-CCITT CRC32, etc. CAN CAN bus interface. For example: http://www.freescale.com/zh-Hans ... y.jsp?code=MCF5227X contains: “FlexCAN” For example: http://www.microchip.com/pagehan ... t/architecture.html contains: “2x CAN 2.0B Ports” USB USB Host: fixed as USB Host USB Slave: fixed as USB Slave USB OTG: can be used as Host or Slave, and can be configured through software Many mobile phones nowadays, if they claim to support USB Host, often have a USB OTG module on the corresponding internal hardware. For the summary of relevant knowledge, please refer to: [Summarization] Regarding whether Android phones support USB host functions, for example: (1) http://www.freescale.com/zh-Hans ... y.jsp?code=MCF5227X, there is: "USB OTG" (2) http://www.microchip.com/pagehan ... t/architecture.html, there is: "Full-speed USB Host/Device/OTG" Video Codec video decoding hardware implementation video decoding includes: JPEG VC1 WMV video decoding, often also involves a pp: post processing, post-processing function. For example, image mixing, graphic rotation, etc. It is also implemented through hardware modules, which is more efficient and faster than software processing. Some information for reference: Chapter 9. Pre- and Post-Processing SAM9M10 Hardware Video Decoder Post Processing Engine Features Audio Codec Audio decoding hardware to achieve audio decoding: · AAC · MP3 · WMA · WMA8 + Microsoft PDDRM · WMA9 + DRM10 · OGG · WAV Audio decoding, often also involves related content such as: Equalization and so on. Clock related modules: Crystal oscillator Crystal, CCU Crystal oscillator, crystal, generates the corresponding clock and then uses CCU, Clock Unit Control, to control the corresponding clock frequency, change it higher or lower, reach the corresponding frequency and then send it to the peripheral modules. LCDC (LCD Controler) LCD controller, LCD controller, LCD display controller can support many different types of external displays. For example: http://www.freescale.com/zh-Hans ... y.jsp?code=MCF5227X, there is a LCDC hardware encryption module crypto, such as AES encryption, etc. DMA is one of the common interfaces. GPIO is one of the common interfaces. I2C is one of the common interfaces. I2C For example: http://www.freescale.com/zh-Hans ... y.jsp?code=MCF5227X, there is an I2C I2S is mainly used for audio. It is often related to sound cards and audio. The previously reprinted post is for reference: I2S standard IDE IDE hard disk. It is more used on the PC side. However, occasionally, IDE hard disks are mounted in embedded systems. Keyboard [Matrix] The keyboard in the embedded system mainly refers to the limited number of keys, so it is often a keyboard matrix. I have worked with the keyboard on the PC before, and its essential principle is similar. You can also refer to it: Scan Code Make Code Break Code in the Keyboard Memory Controller: MPMC The memory controller MPMC can be plugged into various storage media. It mainly refers to SDRAM Nor Flash Flash itself. Although it is divided into Nand Flash and Nor Flash, the word Flash itself often represents Nor Flash itself. It is divided into: Nor Flash sometimes also refers to EEPROM, such as http://www.microchip.com/pagehan ... t/architecture.html: "Up to 512 KB Flash" Nand Flash Nand Flash may involve the bch algorithm. Power Management PMU Power Management Unit is used to manage power. It can control the power supply and voltage of various hardware modules to achieve: · Make the hardware work stably and normally · Implement power consumption management · At normal voltage, the performance is good, but the power consumption is high · At low voltage, the power consumption is reduced accordingly, but the performance is relatively weak. The explanation of wiki is for reference: http://en.wikipedia.org/wiki/Power_Management_Unit Real Time Clock RTC (Real Time Clock) RTC, common, one of the basic functions in embedded systems. It can run normally even when the power is off. For example: http://www.freescale.com/zh-Hans ... y.jsp?code=MCF5227X, there is an RTC SD/MMC, SSP is also one of the common interfaces. Synchronous Serial Port http://en.wikipedia.org/wiki/Synchronous_Serial_Port What is the difference between SSP and SPI interface? http://zhidao.baidu.com/question/247087991.html Touch Panel The touch screen is also related to the display, but it supports touch. TVOUT One of the output formats of the display content. Displayed on the TV. Including the corresponding PAL or NTSC formats. UART/RS232/serial port WatchDog is referred to as WDT JTAG is used to support JTAG port to debug chips belonging to debugging things Ethernet network card, Ethernet card, for example: http://www.microchip.com/pagehan ... t/architecture.html has: "10/100 Ethernet MAC with MII/RMII Interfaces" To summarize the development process of embedded systems, often, more often, it may be to learn and understand the working principles of these peripherals, and then to implement the corresponding drivers. This is often one of the common, typical things to do in embedded development. For more embedded, Internet of Things, and smart hardware learning, please consult Teacher Yu QQ28~59~78~02~03

懒猫爱飞

Well, it's basically summarized. The OP could further refine it. It would be better if you explain each interface in detail. It would be better if you can also explain it with examples. In any case, thank you very much for sharing^_^