Intel PXA270 Optimization Manual page 128

Device A logical or physical entity that performs a function. The actual entity described depends on the context of
the reference. At the lowest level, "device" may refer to a single hardware component, as in a memory device. At a
higher level, it may refer to a collection of hardware components that perform a particular function, such as a USB
interface device. At an even higher level, device may refer to the function performed by an entity attached to the
USB; for example, a data/FAX modem device. Devices may be physical, electrical, addressable, and logical. When
used as a non-specific reference, a USB device is either a hub or a function.
Device Address A seven-bit value representing the address of a device on the USB. The device address is the
default address (00H) when the USB device is first powered or the device is reset. Devices are assigned a unique
device address by the USB System Software.
Device Endpoint A uniquely addressable portion of a USB device that is the source or sink of information in a
communication flow between the host and device. See also endpoint address.
Device Resources Resources provided by USB devices, such as buffer space and endpoints. See also Host
Resources and Universal Serial Bus Resources.
Device Software Software that is responsible for using a USB device. This software may or may not also be
responsible for configuring the device for use.
DMA Direct Memory Access
Downstream The direction of data flow from the host or away from the host. A downstream port is the port on a
hub electrically farthest from the host that generates downstream data traffic from the hub. Downstream ports
receive upstream data traffic.
DQPSK Differential Quadrature Phase Shift Keying a modulation technique used in TDMA.
Driver When referring to hardware, an I/O pad that drives an external load. When referring to software, a program
responsible for interfacing to a hardware device, that is, a device driver.
DSP Digital Signal Processing
DSTN Passive LCD Panel.
Dual band mobile phone A phone that supports both analog and digital technologies by picking up analog signals
when digital signals fade. Most mobile phones are not dual-band.
DWORD Double word. A data element that is two words (i.e., four bytes or 32 bits) in size.
Dynamic Insertion and Removal The ability to attach and remove devices while the host is in operation.
E2PROM See Electrically Erasable Programmable Read Only Memory.
EAV End of active video
EDGE Enhanced Data GSM Environment. A faster version of the GSM standard. It is faster because it can carry
messages using broadband networks that employ more bandwidth than standard GSM networks.
EEPROM See Electrically Erasable Programmable Read Only Memory.
Electrically Erasable Programmable Read Only Memory (EEPROM) Non-volatile re-writable memory
storage technology.
End User The user of a host.
Glossary-4
Intel® PXA27x Processor Family Optimization Guide