Fujitsu MHY2200BS Product/Maintenance Manual page 281

(3) Invalidating caching-target data
Data that is a target of caching on the data buffer is invalidated under the
following conditions:
1)-1 Any command other than the following commands is issued. (All caching-
target data is invalidated.)
READ BUFFER
WRITE BUFFER
RECALIBRATE
FORMAT TRACK
SET FEATURES
SECURITY ERASE UNIT
DEVICE CONFIGURATION
DOWNLOAD MICROCODE
WRITE UNCORRECTABLE EXT
READ LOG (DMA) EXT
WRITE LOG (DMA) EXT
UNSUPPORT COMMAND (INVALID COMMAND)
1)-2 Commands that partially invalidate caching data
READ DMA/READ MULTIPLE/READ SECTOR(S)
READ DMA EXT/READ MULTIPLE EXT/READ SECTOR(S) EXT
READ FP DMA QUEUED
WRITE DMA/WRITE MULTIPLE/WRITE SECTOR(S)
WRITE DMA EXT/WRITE MULTIPLE EXT/WRITE SECTOR(S) EXT
WRITE DMA FUA EXT/WRITE MULTIPLE FUA EXT
WRITE FP DMA QUEUED
SMART
2) A COMRESET is issued or the power is turned off.
3) When HOST CRC ERROR has occurred.
C141-E269
6.4 Read-ahead Cache
6-15