The intervention message response includes the writeback data.

Upon receiving an intervention message from the cache coherency manager, the processor core determines if the intervention message corresponds with any of its own pending data access requests.

Upon receiving an intervention message associated with the writeback request, the processor core unit provides an intervention message response to the cache coherency manager unit indicating that the writeback operation should not be cancelled.

The anchor exchange receives the base station challenge message, and performs the base station challenge to obtain an authentication result.

The method has steps of sending a base station challenge message (40) from a mobile station (16) to an anchor exchange (12A).

When the intervention message associated with the writeback request is received, the cache lines s cache coherency data is examined.

If a request for the same data arrives before the intervention message, the processor core unit provides the requested data and cancels the pending writeback request.

In response to a coherent request, an intervention message is forwarded only to the cores that are defined to be in the same coherence domain as the requesting core.

The cache coherency data associated with cache lines indicates whether a request for data has been received prior to the intervention message associated with the writeback request.