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PEB383 User Manual
July 25, 2011
Integrated Device Technology, Inc.
Confidential - NDA Required
Glossary
Address decode window
The address range defined by a device’s base address registers when operating in non-transparent
addressing mode. If a transaction address on the bus falls within a device’s address decode window,
the device claims the transaction.
Base and limit register
A configuration register that stores memory or I/O address decode information in a device. If the
address of a transaction falls within the window defined by a device’s base and limit registers, the
device claims the transaction. Base and Limit registers are used only by transparent bridges.
Compact PCI
cPCI. It is an adaptation of the
PCI Local Bus Specification (Revision 2.2)
for Industrial and/or
embedded applications that require a more robust mechanical form factor than desktop PCI.
Completer (PCIe)
The device that is targeted by a requester during a PCIe transaction. A requester reads data from a
completer, or writes data to a completer. A requester can be either a root complex or an endpoint
device.
Completer ID
This value uniquely identifies the completer of a transaction request. It consists of a completer’s bus
number, device number, and function number.
Configuration transaction
A read or write access of a PCI device’s configuration registers.
Downstream port
A PCIe port that points in the direction away from the root complex (for example, a root complex port).
Egress port
A PCIe port that transmits a packet to another PCIe device.
Endpoint
A type of PCIe device, or mode of operation, that function as requesters or completers of PCIe
transactions (examples include Ethernet, USB, and graphic devices). If a PCIe port is not configured
as a root complex or a switch then it is considered an endpoint. An endpoint can support up to eight
functions.
Fairness algorithm
Arbitration logic that helps low and high priority devices gain fair access to a peripheral bus. This logic
also helps prevent deadlocks among bus-mastering devices in a system.
Flow control
The method of communicating receive buffer status from a receiver to a transmitter to prevent receive
buffer overflow and to allow transmitter compliance with ordering rules.
Hierarchy
A PCIe fabric of all devices and links associated with a root complex. The devices can be connected
either directly or indirectly (through switches and bridges) to the root complex.
Hot swap
This refers to the process of inserting and extracting CompactPCI boards from an active system
without adversely affecting system operation.
Ingress port
A PCIe port that receives a packet from another PCIe device.
Link
An interconnection between two PCIe devices. A link consists of either x1, x2, x4, x8, x16, or x32
pairs of signals between two devices. Each grouping of signals is referred to as a
lane
.
Memory-mapped I/O
MIO. Memory-mapped I/O is used for non-prefetchable PCI memory transactions.