A number of coherence domains are maintained among the multitude of processing cores disposed in a microprocessor. A cache coherency manager defines the coherency relationships such that coherence traffic flows only among the processing cores that are defined as having a coherency relationship. The data defining the coherency relationships between the processing cores is optionally stored in a programmable register. For each source of a coherent request, the processing core targets of the request are identified in the programmable register. 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. If a cache hit occurs in response to a coherent read request and the coherence state of the cache line resulting in the hit satisfies a condition, the requested data is made available to the requesting core from that cache line.