Fujitsu MHV2040BH, Product Manual

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Operations
6-18 C141-E224
data that is a target of caching and remains before a full hit, the data is retained
when execution of the command is completed. This is done so that a new read-
ahead operation is not performed. If the full hit command is received during the
read-ahead operation, a transfer of the read requested data starts while the read-
ahead operation is in progress.
1) An example is the state shown below where the previous read command is
executing sequential reading. First, HAP is set at the location where hit data
is stored.
HAP (It is reset to the hit data location for transfers.)
HAP end location of the previous read command
DAP end location of the previous read command
Cache data Full hit data Cache data
HAP
DAP
2) The read requested data is transferred, and a new read-ahead operation is not
performed.
(stop)
HAP
Cache data Full hit data Cache data