The Unabridged Pentium 4 IA32 Processor Genealogy

The Data Phase Signal Group

Table 51-2 on page 1247 defines the signals used during the Data Phase of a transaction.

Table 51-2. Data Phase-related Signals

Signal(s)	Description
DBSY#	Data Bus Busy. Asserted by the agent that will drive data on the data bus (i.e., the Response Agent on a read; the Request Agent on a write; the Snoop Agent on a snoop hit on modified line) to indicate that it is taking ownership of the Data Bus. DBSY# is deasserted at one of the following times: In the same BCLK cycle wherein the final data is transferred. One BCLK cycle after the final data is transferred (this is referred to as Relaxed deassertion of DBSY#).
DRDY#	Data Ready. Asserted by the agent sourcing data to indicate that valid data is being driven onto the Data ...