Philips 202P4, Service Manual

Page: 120 / 121

General Troubleshooting Guide
112
9
Go to cover page
202P4 M25P
USB
USB = Universal Serial Bus
USB automatically determines resources (like driver software and bus bandwidth)
required by peripherals.
USB makes necessary resources available without user intervention.
It is designed to meet Microsoft Plug and Play (PnP) specification, meaning users can install,
and hot-swap devices without long installation procedures and reboots.
It allows 127 devices to run at the same time on the bus.
USB bus provides two types of data transfer speed -- 1.5Mbps and 12Mbps
and it can provide a maximum of 500mA of current to devices attached on the bus.
Universal means all peripherals share the same connector.
Serial simply defines devices can daisy chain together.
Universal Serial Bus 1.1, the de facto external connectivity standard for Mac and PC,
has picked up the speed after its slow adoption by peripheral manufacturers, users and PC OEMs.
USB 2.0 :
Drafted by Compaq, Hewlett Packard, Intel, Lucent, Microsoft, NEC and Philips,
USB Specification version 2.0 will increase device data throughout
up to 480Mbps, 40 times faster than USB 1.1 devices.
20