Intel PXA27 Series Design Manual page 287

Glossary
PMIC. Power Management Integrated Circuit is a highly integrated device with both required and optional features
to support the nine power domains on the PXA27x processor, as well as dynamic voltage management features.
Polling. Asking multiple devices, one at a time, if they have any data to transmit.
POR. See Power On Reset
Port. Point of access to or from a system or circuit. For the USB, the point where a USB device is attached.
Power On Reset (POR). Restoring a storage device, register, or memory to a predetermined state when power is
applied.
Process ID. Process Identifier.
Programmable Data Rate. Either a fixed data rate (single-frequency endpoints), a limited number of data rates (32
KHz, 44.1 KHz, 48 KHz, ...), or a continuously programmable data rate. The exact programming capabilities of an
endpoint must be reported in the appropriate class-specific endpoint descriptors.
Protocol. A specific set of rules, procedures, or conventions relating to format and timing of data transmission
between two devices.
PSP. Programmable Serial Protocol
PWM. Pulse-Width Modulator
QBS. Qualification By Similarity. A technique allowed by JEDEC for part qualification when target parameters are
fully understood and data exist to warrant omitting a specific test.
QAM. Quadrature Amplitude Modulation. A coding scheme for digital data.
QPSK. Quadrature Phase Shift Keying. A convention for encoding digital data into a signal using phase-modulated
communications.
RA. See Rate Adaptation.
Radio Frequency Device. These devices use radio frequencies to transmit data. One typical use is for bar code
scanning of products in a warehouse or distribution center, and sending that information to an ERP database.
Rate Adaptation. The process by which an incoming data stream, sampled at Fs i, is converted to an outgoing data
stream, sampled at Fs o, with a certain loss of quality, determined by the rate adaptation algorithm. Error control
mechanisms are required for the process. Fs i and Fs o can be different and asynchronous. Fs i is the input data rate
of the RA; Fs o is the output data rate of the RA.
Request. A request made to a USB device contained within the data portion of a SETUP packet.
Retire. The action of completing service for a transfer and notifying the appropriate software client of the
completion.
RGBT. Red, Green, Blue, Transparency
ROM. Read Only Memory
Root Hub. A USB hub directly attached to the Host controller. This hub (tier 1) is attached to the host.
Root Port. The downstream port on a Root Hub.
RTC. Real-Time Clock
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Intel PXA27x Processor Family Design Guide Glossary-11