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--- usb [2016/06/22 18:26]
shuyi
+++ usb [2022/08/16 21:37] (当前版本)
gongyu
@@ 行 1: / 行 1: @@
+## USB - 通用串行总线
 USB, short for Universal Serial Bus, is an industry standard developed in the mid-1990s that defines the cables, connectors and communications protocols used in a bus for connection, communication, and power supply between computers and electronic devices. It is currently developed by the USB Implementers Forum (USB IF).
 USB was designed to standardize the connection of computer peripherals (including keyboards, pointing devices, digital cameras, printers, portable media players, disk drives and network adapters) to personal computers, both to communicate and to supply electric power. It has become commonplace on other devices, such as smartphones, PDAs and video game consoles. USB has effectively replaced a variety of earlier interfaces, such as parallel ports, as well as separate power chargers for portable devices.
-====== Overview ======
+### 1. 概述
 In general, there are three basic formats of USB connectors: the default or standard format intended for desktop or portable equipment (for example, on USB flash drives), the mini intended for mobile equipment (now deprecated except the Mini-B, which is used on many cameras), and the thinner micro size, for low-profile mobile equipment (most modern mobile phones). Also, there are 5 modes of USB data transfer, in order of increasing bandwidth: Low Speed (from 1.0), Full Speed (from 1.0), High Speed (from 2.0), SuperSpeed (from 3.0), and SuperSpeed+ (from 3.1); modes have differing hardware and cabling requirements. USB devices have some choice of implemented modes, and USB version is not a reliable statement of implemented modes. Modes are identified by their names and icons, and the specifications suggests that plugs and receptacles be colour-coded (SuperSpeed is identified by blue).
@@ 行 13: / 行 15: @@
 Non-obviously, the micro format is the most durable from the point of designed insertion lifetime. The standard and mini connectors were designed for less frequently than daily connections, with a design lifetime of 1,500 insertion-removal cycles.[7] (Improved Mini-B connectors have reached 5,000-cycle lifetimes.) Micro connectors were designed with frequent charging of portable devices in mind; not only is design lifetime of the connector improved to 10,000 cycles, but it was also redesigned to place the flexible contacts, which wear out sooner, on the easily replaced cable, while the more durable rigid contacts are located in the receptacles. Likewise, the springy component of the retention mechanism (parts that provide required gripping force) were also moved into plugs on the cable side.
-====== History ======
+### 2. 历史
 <WRAP centeralign>{{:usb_icon.svg.png?200|}}USB基本标志</WRAP>
@@ 行 37: / 行 36: @@
 In December 2014, USB-IF submitted USB 3.1, USB Power Delivery 2.0 and USB Type-C specifications to the IEC (TC 100 – Audio, video and multimedia systems and equipment) for inclusion in the international standard IEC 62680 Universal Serial Bus interfaces for data and power, which is currently based on USB 2.0.
-====== Version history ======
+### 3. 不同版本
-===== Overview =====
+^发布版本	|发布日期	|最高速率	 |说明|
-^Release name	|Release date	|Maximum transfer rate	 |Note|
 ^USB 0.8	|December 1994	|	|Prerelease|
 ^USB 0.9	|April 1995	|	|Prerelease|
@@ 行 52: / 行 49: @@
 ^USB 3.1	|July 2013	|SuperSpeed+ (10 Gbit/s)	|Also referred to as USB 3.1 Gen 2 by USB 3.1 standard|
-===== Power related specifications =====
+### 4. 与功率相关的指标
-^Release name	|Release date	|Max. power	|Note|
+^发布名字	|发布日期	|最大功率	|说明|
 ^USB Battery Charging 1.0	|2007-03-08	|5 V, 1.5 A|
 ^USB Battery Charging 1.1	|2009-04-15|
@@ 行 66: / 行 63: @@
 ^USB Power Delivery revision 2.0 (version 1.2)	|2016-03-25	|20 V, 5 A|
-===== USB 1.x =====
+#### 4.1 USB 1.x
 Released in January 1996, USB 1.0 specified data rates of 1.5 Mbit/s (Low Bandwidth or Low Speed) and 12 Mbit/s (Full Bandwidth or Full Speed). It did not allow for extension cables or pass-through monitors, due to timing and power limitations. Few USB devices made it to the market until USB 1.1 was released in August 1998, fixing problems identified in 1.0, mostly related to using hubs. USB 1.1 was the earliest revision that was widely adopted and led to Legacy-free PCs.
-===== USB 2.0 =====
+#### 4.2 USB 2.0
 The Hi-Speed USB Logo
 A USB 2.0 PCI expansion card
-USB 2.0 was released in April 2000, adding a higher maximum signaling rate of 480 Mbit/s (High Speed or High Bandwidth), in addition to the USB 1.x Full Speed signaling rate of 12 Mbit/s. Due to bus access constraints, the effective throughput of the High Speed signaling rate is limited to 280 Mbit/s or 35 MB/s.[26]
+USB 2.0 was released in April 2000, adding a higher maximum signaling rate of 480 Mbit/s (High Speed or High Bandwidth), in addition to the USB 1.x Full Speed signaling rate of 12 Mbit/s. Due to bus access constraints, the effective throughput of the High Speed signaling rate is limited to 280 Mbit/s or 35 MB/s.
-Further modifications to the USB specification have been made via Engineering Change Notices (ECN). The most important of these ECNs are included into the USB 2.0 specification package available from USB.org:[27]
+Further modifications to the USB specification have been made via Engineering Change Notices (ECN). The most important of these ECNs are included into the USB 2.0 specification package available from USB.org
 Mini-A and Mini-B Connector ECN: Released in October 2000.
@@ 行 97: / 行 91: @@
 Link Power Management Addendum ECN: Released in July 2007.
 This adds sleep, a new power state between enabled and suspended states. Device in this state is not required to reduce its power consumption. However, switching between enabled and sleep states is much faster than switching between enabled and suspended states, which allows devices to sleep while idle.
-Battery Charging Specification 1.2:[28] Released in December 2010.
+Battery Charging Specification 1.2 Released in December 2010.
 Several changes and increasing limits including allowing 1.5 A on charging ports for unconfigured devices, allowing High Speed communication while having a current up to 1.5 A and allowing a maximum current of 5 A.
-===== USB 3.0 =====
+#### 4.3 USB 3.0
 Main article: USB 3.0
@@ 行 113: / 行 107: @@
 Low-power and high-power devices remain, but those using SuperSpeed gain increased current of 150 mA and 900 mA, respectively.[31] Additionally, there is a Battery Charging Specification (Version 1.2 – December 2010), which increases the power handling capability to 1.5 A but does not allow concurrent data transmission.[28] The Battery Charging Specification requires that the physical ports themselves be capable of handling 5 A of current[citation needed] but limits the maximum current drawn to 1.5 A.
-===== USB 3.1 =====
+#### 4.4 USB 3.1
 A January 2013 press release from the USB group revealed plans to update USB 3.0 to 10 Gbit/s.[32] The group ended up creating a new USB specification, USB 3.1, which was released on 31 July 2013,[33] replacing USB 3.0 standard. USB 3.1 specification takes over existing USB 3.0's SuperSpeed USB transfer rate, also referred to as USB 3.1 Gen 1, and introduces a faster transfer rate called SuperSpeed USB 10 Gbps, also referred to as USB 3.1 Gen 2,[25] putting it on par with a single first-generation Thunderbolt channel. The new mode's logo features a caption stylized as SUPERSPEED+. The USB 3.1 standard increases the data signaling rate to 10 Gbit/s, double that of SuperSpeed USB, and reduces line encoding overhead to just 3% by changing the encoding scheme to 128b/132b.[34] The first USB 3.1 implementation demonstrated transfer speeds of 7.2 Gbit/s.[35]
@@ 行 119: / 行 113: @@
 The USB 3.1 standard is backward compatible with USB 3.0 and USB 2.0.
-===== USB Type-C =====
+#### 4.5 USB Type-C
 The USB Type-C plug