|Non-Confidential||PDF version||ARM 100052_0001_00_en|
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The Fully-coherent Home Node (HN-F) is responsible for managing part of the address space.
The HN-F consists of the following:
|L3 cache||The L3 cache is a distributed, mostly exclusive last-level cache. The L3 cache-allocation policy is exclusive for data lines, except where sharing patterns are detected, and pseudo-inclusive for code lines, as controlled by the RN-Fs, meaning that all code lines can be allocated into the L3 on the initial request.|
|Combined PoS/PoC||The combined Point-of-Serialization/Point-of-Coherency (PoS/PoC) is responsible for the ordering of all memory requests sent to the HN-F. This includes coherency ordering, that is, serialization of multiple outstanding requests and actions to the same line, and request ordering as required by the RNs.|
|Snoop filter||The snoop filter reduces snoop coherency traffic in the system by tracking cache lines that are present in the RN-Fs in the system, and generally converting snoop broadcasts to directed snoops. This substantially reduces the quadratic growth in snoop response traffic that might otherwise be required without the snoop filter.|
Each HN-F in the system is configured to manage a specific portion of the overall address space, and all three functionalities are included in this management responsibility:
Therefore, the entire memory address space is managed through the combination of all HN-Fs in the system, except for the memory-mapped I/O address space.