Intel PXA27 Series Design Manual page 284

Glossary
IBIS. I/O Buffer Information. Specification is a behavioral description of the I/O buffers and package
characteristics of a semiconductor device. IBIS models use a standard format to make it easier to import data into
circuit simulation software packages.
iDEN. Integrated Digital Enhanced Network. A technology that allows users to access phone calls, two-way radio
transmissions, paging and data transmissions from one wireless device. iDEN was developed by Motorola and
based on TDMA.
Interrupt Request (IRQ). A hardware signal that allows a device to request attention from a host. The host
typically invokes an interrupt service routine to handle the condition that caused the request.
Interrupt Transfer. One of the four USB transfer types. Interrupt transfer characteristics are small data, non-
periodic, low-frequency, and bounded-latency. Interrupt transfers are typically used to handle service needs. See
also Transfer Type.
I/O Request Packet. An identifiable request by a software client to move data between itself (on the host) and an
endpoint of a device in an appropriate direction.
IrDA. Infrared Development Association
IRP. See I/O Request Packet.
IRQ. See Interrupt Request.
ISI. Inter-signal interference. Data ghosting caused when multi-path delay causes previous symbols to interfere
with the one currently being processed.
ISM. Industrial, Scientific, and Medical band. Part of the wireless spectrum that is less regulated, such as 802.11.
Isochronous Data. A stream of data whose timing is implied by its delivery rate.
Isochronous Device. An entity with isochronous endpoints, as defined in the USB Specification, that sources or
sinks sampled analog streams or synchronous data streams.
Isochronous Sink Endpoint. An endpoint that is capable of consuming an isochronous data stream that is sent by
the host.
Isochronous Source Endpoint. An endpoint that is capable of producing an isochronous data stream and sending
it to the host.
Isochronous Transfer. One of the four USB transfer types. Isochronous transfers are used when working with
isochronous data. Isochronous transfers provide periodic, continuous communication between host and device. See
also Transfer Type.
Jitter. A tendency toward lack of synchronization caused by mechanical or electrical changes. More specifically,
the phase shift of digital pulses over a transmission medium.
kbps. Transmission rate expressed in kilobits per second. A measurement of bandwidth in the U.S.
kBps. Transmission rate expressed in kilobytes per second.
KPC. Keypad Interface Control
LCD. Liquid Crystal Display
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Glossary-8 Intel PXA27x Processor Family Design Guide