MPC8544COMEDEV Freescale Semiconductor, MPC8544COMEDEV Datasheet - Page 1151

Manufacturer Part Number

MPC8544COMEDEV

KIT DEV EXPRESS MPC8544COM

Manufacturer

Freescale Semiconductor

For Use With/related Products

Lead Free Status / RoHS Status

Lead free / RoHS Compliant

PCI Express Interface Controller

Functional Description

The PCI Express protocol relies on a requestor/completer relationship where one device requests that some

desired action be performed by some target device and the target device completes the task and responds.

Usually the requests and responses occur through a network of links, but to the requestor and to the

completer, the intermediate components are transparent.

Intermediate

Component(s)

Figure 18-122. Requestor/Completer Relationship

Each PCI device is divided into two halves-transmit (TX) and receive (RX), and each of these halves is

further divided into three layers—transaction, data link, and physical—as shown in

Logical Sub-block

Electrical Sub-block

Figure 18-123. PCI Express High-Level Layering

Packets are formed in the transaction layer (TLPs) and data link layer (DLLPs), and each subsequent layer

adds the necessary encodings and framing—as shown in

18-124. As packets are received, they are

decoded and processed by the same layers but in reverse order, so they may be processed by the layer or

by the device application software.

MPC8544E PowerQUICC III Integrated Host Processor Family Reference Manual, Rev. 1

Freescale Semiconductor