最後更新: 2015-11-04

目錄

 

 

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Check Port Version

 

lsusb -t

• 12M = 12MBit/s = USB1
• 480M = 480MBit/s = USB2
• 5000M = 5000MBit/s = USB3.0 aka USB3.1 gen. 1
• 10000M = 10000MBit/s = USB3.1 gen. 2

 

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Lenght

 

USB 3.0 (Super Speed)[xhci_hcd]

Standard does not directly specify a maximum cable length

( all cables meet an electrical specification )

USB 2.0  (High Speed) [ehci_hcd 相容於 UHCI / OHCI ]

up to 5 meters

( cable delay be less than 5.2 ns per meter )

USB 1.0 (Full speed) [UHCI / OHCI ]

the limit is 3 meters

USB Hubs

max. 5 USB hubs

Active Extension Cables

Lenght: 30 meters

contain electronics which regenerate the USB signal.

Cable

Twisted pair

 

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Speed

 

USB 3.1

Gen1 at 5 Gbps [Standard-A, Standard-B, Micro-B] (同 USB 3.0 無大分別, 主要用來 replace USB 3.0)

• data signaling rate over 1 lane using 8b/10b encoding
• Disk throughput: 500 Mbyte/s

Gen2 at 10 Gbps (SuperSpeed+)[USB Type-C]

• data signaling rate over 1 lane using 128b/132b encoding
• 名稱: SuperSpeed+

USB 3.0

名稱: SuperSpeed

速度: data signaling rate of 5.0 Gbit/s (payload throughput is 4 Gbit/s)

供電: come in low-power and high-power variants, providing 150 mA and 900 mA respectively

Pinouts: 4 + 4(differential pairs) + 1(GND_DRAIN)[未必要]

USB 2.0

High: 480 Mbit/s

Due to bus access constraints, the effective throughput => 280 Mbit/s (35 MB/s)

(480 Mbit/s = Clock speed, 280 Mbit/s 係 BOT Protocol 的 Limit 來)

BOT = Bulk Only Transport

Half-Duplex

Bulk-Only Protocol

     Out >
Host       Device
     < IN

1. CBW

2. CSW

USB 1.x

Low: 1.5 Mbit/s
Full: 12 Mbit/s

 

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Pinout

 

USB 2.0

plug connector (公)

4 3 2 1
==== 膠

receptacle connector

==== 膠
1 2 3 4

Pin 的功能

1     VCC     Red       +5 VDC
2     D-      White     Data -
3     D+      Green     Data +
4     GND     Black     Ground

 

drain wire

stranded wire you find interleaved with the wrapping foil inside shielded cables

permits a continuous, low-resistance connection to the cable's metallic shield, resulting in very effective grounding.

differential pairs

優點: 抗干擾能力強

(干擾噪聲一般會等值同時的被加載到兩根信號線上, 而其差值為0. 即噪聲對信號的邏輯意義不產生影響)

走線: 必須是等長、等寬、緊密靠近、且在同一層面的兩根線

 

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PCIe to USB 3.X

 

ORICO 4 Port USB3.0 PCI-E Expansion Card

Chip

• PVU3-4P: VL805 (VIA Lab) [4 port]
• PNU-4U: NEC D720201 [4 port]      # 較好支援 Linux

USB 3.1: ORICO PA31-2P ( A Port X 2) / PA31-AC (1 A, 1 C)

Chip: ASM1142

Support PCI Express Gen2x2 or Gen3x1

USB Type-C

• CC腳               # Configuration Channel)

Source ---C1/C2---- Sink Device    # 接受電力的設備
                        |
                       Rd          # Pull-down Resistor

 

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SATA to USB Bridge

 

JMS561

• Dual SATA 6Gbps Ports
• RAID 0 / RAID 1 / JBOD / Multiplier
• Comply with UASP

 

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Other

 

• usbmount
• Poweroff usbdisk
• UAS
• Linux boot 唔 detect USB
• IC - JMicron