Themis TA64, Руководство по оборудованию

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E-3
Themis Computer
E—Glossary
LVD : Low-Voltage Differential (Device).
may : A keyword indicating flexibility of choice with no implied preference.
MHz : Megahertz (millions of cycles per second, 10
6
cps); unit of frequency.
MII : Medium Independent Interface.
MMU : Memory Management Unit.
NA or N/A : Not Applicable.
NC or N/C : No Connection.
NVRAMRC : Acronym for N on- V olatile R andom- A ccess M emory R un C ommand.
This refers to the executable BIOS script that is written in the NVRAM. Other
text information or binary data may exist in the NVRAM, but is not referred as
NVRAMRC.
PCB : Printed Circuit Board.
PCI : Peripheral Component Interconnect (bus). A high-performance 32- or 64-bit
bus with multiplexed address and data lines, as specified in the PCI Local Bus
Specification, Revision 2.1, June 1, 1995.
PHY : Physical transceiver or sublayer.
Physical Address: An address that maps to real physical memory or I/O device
space.
PIO : Programmed I/O. A method of accessing devices under UNIX as special files
(as opposed to mapping the physical address range to a process’s virtual
address space).
PLD : Programmable Logic Device.
PLL : Phase-Locked Loop. A feedback control system that automatically adjusts the
phase of a locally generated signal to match the phase of an input signal.
PMC : PCI Mezzanine Card.
POR : Power-On Reset.
Probing : A process implemented in the firmware and software to identify onboard
hardware devices and add-on cards on the PCI bus. The probing process cre-
ates the device-tree.
R0 : An abbreviation used to indicate “Read Zero.” When software attempts to read