HyperTransport™ System Architecture

The Ordering Rules

HyperTransport packet ordering rules are divided into groups: general rules, rules for upstream I/O ordering, and rules for downstream ordering. Even the peer-to-peer example in Figure 6-1 on page 121 can be broken into two parts: the request moving to the bridge (covered by upstream ordering rules) and the reflection of the request downstream to the peer-to-peer target (covered by downstream I/O ordering rules). Refer to Chapter 20, entitled "I/O Compatibility," on page 457 for a discussion of ordering when packets move between HyperTransport and another protocol (PCI, PCI-X, or AGP).

General I/O Ordering Limits

Ordering Covers Targets At Same Hierarchy Level

Ordering rules only apply to the order in which operations are detected ...