Transaction Layer Overview

Layering Diagram Highlighting the Transaction Layer

At a high level, the key aspects of the Transaction Layer are:

• A pipelined full split-transaction protocol
• Mechanisms for differentiating the ordering and processing requirements of Transaction Layer Packets (TLPs)
• Credit-based flow control
• Optional support for data poisoning and end-to-end data integrity detection.

The Transaction Layer comprehends the following:
TLP construction and processing
Association of transaction-level mechanisms with device resources including:
• Flow Control
• Virtual Channel management
Rules for ordering and management of TLPs
• PCI/PCI-X compatible ordering
• Including Traffic Class differentiation
This chapter specifies the behaviors associated with the Transaction Layer.