PCI Express Terms and Acronyms (Four)

Data Link Layer Packet, DLLP	A Packet generated in the Data Link Layer to support Link management functions.
data payload	Information following the header in some packets that is destined for consumption by the targeted Function receiving the Packet (for example, Write Requests or Read Completions).
deasserted	The inactive logical state of a conceptual or actual signal.
device	1. A physical or logical entity that performs a specific type of I/O. 2. A component on either end of a PCI Express Link. 3. A common imprecise synonym for Function, particularly when a device has a single Function.
Device	A collection of one or more Functions identified by common Bus Number and Device Number.
DFT	Design for Testability.
Downstream	1. The relative position of an interconnect/System Element (Port/component) that is farther from the Root Complex. The Ports on a Switch that are not the Upstream Port are Downstream Ports. All Ports on a Root Complex are Downstream Ports. The Downstream component on a Link is the component farther from the Root Complex. 2. A direction of information flow where the information is flowing away from the Root Complex.
DWORD, DW	Four bytes. Used in the context of a data payload, the 4 bytes of data must be on a naturally aligned 4-byte boundary (the least significant 2 bits of the byte address are 00b).
Egress Port	The transmitting Port; that is, the Port that sends outgoing traffic.
Electrical Idle	The state of the output driver in which both lines, D+ and D-, are driven to the DC common mode voltage.