Patent Number: 6,324,617

Title: Method and system for communicating tags of data access target and castoutvictim in a single data transfer

Abstract: A combined address bus transaction contains the address tag for a dataaccess operation target, the address tag for a victim to be replaced, andthe address index field identifying the congruence class including boththe target and the victim. Directory state information such as coherencystate and/or LRU position for the cast out victim may also be appended tothe index field and target and victim address tags within the busoperation. Address bus bandwidth utilization is thereby improved,eliminating duplicate transmission of the index field employed by separatedata access and cast out operations in accordance with the existingpractice. The victim may be prospectively selected concurrently with thedetermination of whether the target may be found within the storage deviceforming the combined address, improving overall performance for thatdevice.

Inventors: Arimilli; Ravi Kumar (Austin, TX), Dodson; John Steven (Pflugerville, TX), Guthrie; Guy Lynn (Austin, TX), Joyner; Jody B. (Austin, TX), Lewis; Jerry Don (Round Rock, TX)


International Classification: G06F 12/08 (20060101); G06F 012/00 ()

Expiration Date: 11/27/2014