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System Support
Link Layer
The link layer provides data integrity by adding a sequence information prefix and a CRC suffix to the packet created by the transaction layer.
Physical Layer
The PCIe bus uses a
System Board
Device A
TX
RX
PCI Express Card
Device B
Figure 4-1. PCIe Bus Lane
Each byte is transferred using 8b/10b encoding. which embeds the clock signal with the data. Operating at a 2.5 Gigabit transfer rate, a single lane can provide a data flow of 200 MBps. The bandwidth is increased if additional lanes are available for use. During the initialization process, two PCIe devices will negotiate for the number of lanes available and the speed the link can operate at. In a x1 (single lane) interface, all data bytes are transferred serially over the lane. In a
4.2.3 Option ROM Mapping
During POST, the PCI bus is scanned for devices that contain their own specific firmware in ROM. Such option ROM data, if detected, is loaded into system memory's DOS compatibility area (refer to the system memory map shown in chapter 3).
4.2.4 PCI Interrupts
Eight interrupt signals (INTA- thru
4.2.5 PCI Power Management Support
This system complies with the PCI Power Management Interface Specification (rev 1.0). The PCI Power Management Enable
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