The Unabridged Pentium 4 IA32 Processor Genealogy

Five Example Scenarios

A Transaction that Doesn't Transfer Data

Figure 51-1 on page 1249 illustrates a transaction that doesn't require a data transfer. This would include:

1. The Special transaction.

2. A transaction that receives a retry response.

3. A transaction that receives a hard failure response.

4. A read transaction that receives a deferred response (the data will be transferred at a later time in a subsequent Deferred Reply transaction) and doesn't hit on a modified line (the case where it hits a modified line is described in “A Read that Hits a Modified Line” on page 1262).

5. A Memory Code or Data Read or a Memory Read and Invalidate for 0 bytes (that does not hit on a modified line).

Figure 51-1. Example 1: Transaction That Doesn't Require Data Transfer ...