User guide

Virtex-5 FPGA Integrated Endpoint Block www.xilinx.com 115
UG197 (v1.5) July 22, 2009
R
S
Sideband
A signal that is implemented with its own wire. Communication using
a sideband signal is not “in-band”. Required by certain PCI Express
form factors.
Sticky register
A register that retains its state through a hot reset.
Switching fabric
The combination of hardware and software that moves data coming in
to a network node out the correct port to the next node in the network.
The switching fabric includes data buffers and the use of shared
memory, the switching units in a node, the integrated circuits that they
contain, and the programming that allows switching paths to be
controlled. The switching fabric is independent of the bus technology
and infrastructure used to move data between nodes and also separate
from the router. The term is sometimes used to mean collectively all
switching hardware and software in a network.
T
TL
Transaction Layer.
TLP
Transaction Layer Packet. A Packet generated in the Transaction Layer
to convey a Request or Completion.
Transaction Layer
The uppermost of the three layers of the PCI Express architecture. See
“Physical Layer” on page 19.
U
V
VC
Virtual channel.
Virtual channel
Virtual connections between two PCI Express devices based on
priority-based servicing. A PCI Express Link can support one or