• Errata for “USB Revision 2.0 April 27, 2000” as of 12/7/2000• Errata for “USB Revision 2.0 April 27, 2000” as of 12/7/2000• Pull-up / Pull-down Resistors (USB Engineering Change Notice)• Suspend Current Limit Changes (USB Engineering Change Notice)• Device Capacitance (USB Engineering Change Notice)• USB 2.0 Connect Timing Update (USB Engineering Change Notice as of April 4,2013)• USB 2.0 VBUS Max Limit (USB Engineering Change Notice)• On-The-Go and Embedded Host Supplement to the USB Revision 2.0 Specification,Revision 2.0 version 1.1a, July 27, 2012• Maximum VBUS Voltage (USB OTGEH Engineering Change Notice)• Universal Serial Bus Micro-USB Cables and Connectors Specification, Revision1.01, 200733.2.2 USBThe USB is a cable bus that supports data exchange between a host computer and a widerange of simultaneously accessible peripherals. The attached peripherals share USBbandwidth through a host-scheduled, token-based protocol. The bus allows peripherals tobe attached, configured, used, and detached while the host and other peripherals are inoperation.USB software provides a uniform view of the system for all application software, hidingimplementation details that make application software more portable. It manages thedynamic attach and detach of peripherals.There is only one host in any USB system. The USB interface to the host computersystem is referred to as the Host Controller.There may be multiple USB devices in any system such as human interface devices,speakers, printers, etc. USB devices present a standard USB interface in terms ofcomprehension, response, and standard capability.The host initiates transactions to specific peripherals, whereas the device responds tocontrol transactions. The device sends and receives data to and from the host using astandard USB data format. USB 2.0 full-speed /low-speed peripherals operate at 12Mbit/sor 1.5 Mbit/s.Chapter 33 Universal Serial Bus (USB) FS SubsystemKL27 Sub-Family Reference Manual , Rev. 5, 01/2016Freescale Semiconductor, Inc. 531
