High Speed USB

Specification

  • USB High Speed was introduced in the year 2000 as part of the USB 2.0 specification.
  • Maximum theoretical bandwidth is 480 Mbit/s.
  • Uses four data lines - Power (5 V), Ground, and two data lines (D+ and D-).
  • Half-Duplex differential signaling on D+ and D-.
  • Uses the traditional USB connectors.

Enumeration

High-speed devices begin the enumeration process identical to full-speed devices. High-speed devices announce to the Host that they are ready to be enumerated by asserting a 5 V signal on D+ through the use of a 1.5 kΩ pull-up resistor. During the 20 ms enumeration RESET signal sent by the Host, the Device executes the High-Speed negotiation process. Upon completing this negotiation the Device, Host, and Hub port connecting the Device will operate in High-Speed mode.

Differences with Full Speed USB

Microframes

High-speed USB was designed to coexist with full-speed USB. The designers speculated many systems would have a Host that could simultaneously offer support for full and high-speed devices. To achieve compatibility, eight high-speed microframes are completed within 1 ms.

Frame Size and Transfer Types

HIGH SPEED Frame size: 125 μs

Supported
Transfer
Types		 Maximum
Size of
Transfer		 Transfers
per frame		 Maximum
Theoretical
Throughput
Control 64 bytes 1 64 kByte/s
Interrupt 1024 bytes up to 3 24 MByte/s
Bulk 512 bytes up to 13 53 MByte/s
Isochronous 1024 bytes up to 3 24 MByte/s

USB Bus States and Signal Levels

HS USB
Bus States		 Bus Levels
Differential "1" D+ high , D- low
Differential "0" D+ low , D- high
Single Ended 0 (SE0) D+ low , D- low
Single Ended 1 (SE1) D+ high, D- high Invalid condition!
Data J state Differential "1"
Data K State Differential "0"
Idle Data J
Resume Data K
Start of Packet (SOP) switches from Idle to Data K
End of Packet (EOP) SE0 for 2 bits, followed by Data J for 1 bit
Disconnect SE0 >= 2 μs
Connect Idle for 2.5 μs
Reset SE0 >= 2 μs

 Learn More

Developing USB with Microchip
USB Speeds and Specifications
USB Power Delivery
Type-C

  Return to Top

© 2020 Microchip Technology, Inc.
Notice: ARM and Cortex are the registered trademarks of ARM Limited in the EU and other countries.
Information contained on this site regarding device applications and the like is provided only for your convenience and may be superseded by updates. It is your responsibility to ensure that your application meets with your specifications. MICROCHIP MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND WHETHER EXPRESS OR IMPLIED, WRITTEN OR ORAL, STATUTORY OR OTHERWISE, RELATED TO THE INFORMATION, INCLUDING BUT NOT LIMITED TO ITS CONDITION, QUALITY, PERFORMANCE, MERCHANTABILITY OR FITNESS FOR PURPOSE. Microchip disclaims all liability arising from this information and its use. Use of Microchip devices in life support and/or safety applications is entirely at the buyer's risk, and the buyer agrees to defend, indemnify and hold harmless Microchip from any and all damages, claims, suits, or expenses resulting from such use. No licenses are conveyed, implicitly or otherwise, under any Microchip intellectual property rights.