Fujitsu MHS2030AT - 2.5" Notebook 30GB Drive Product Manual page 234

Operations
4) The following cache valid data is for the read command that is executed next:
Cache valid data
START LBA
(Logical block address)
6.4.3.2 Sequential reading
The read-ahead operation is performed for the read buffer when the read
command that is targeted at a sequential address is received after execution of the
read command is completed.
1. Sequential command immediately after non-sequential command
1) When the sequential read command is received, DAP and HAP are set in the
sequential address of the last read command, and read requested data is read.
Hit error data
2) During reading of read requested data, the request data that has already been
read is sent to the host system.
Hit error data
3) When reading of read requested data is completed and transfer of the read
requested data to the host system is completed, the read-ahead operation
continues until a certain amount of data is stored.
Hit error data
6-16
HAP
DAP
HAP
Read requested data
DAP
HAP
Read requested data Read-ahead data
LAST LBA
Free space
Free space
Free space
DAP
C141-E171-03EN