Interface
5.4.2 PIO data-in command protocol
Data of one or more sectors is transferred from the device to the host.
2) If an error remaining in the device prevents command execution, the device
sends the RegDH FIS with 1 set in the I bit.
Execution of the following commands involves data transfers from the device to
the host system:
• IDENTIFY DEVICE
• READ SECTOR(S) (EXT)
• READ MULTI (EXT)
• READ BUFFER
• SMART READ DATA
• SMATR READ LOG SECTOR
• READ LOG EXT
• DEVICE CONFIGRATION IDENTIFY
An outline of this protocol is as follows:
1) The device receives a PIO data-in command with the RegHD FIS.
3) When the device is ready to send data, it sets 0 in the BSY bit, 1 in the DRQ
bit, and 1 in the I bit of the Status field of the PIO Setup FIS, then sends this
FIS to the host. At this time, if the requested data is read from the last sector
to be processed, the device sets 0 in both the BSY bit and DRQ bit of the
E_Status field. Otherwise, the device sets 1 in the BSY bit and 0 in the DRQ
bit of the E_Status field.
4) The device sends the DATA FIS to the host.
5) When all data has been transferred, command execution is completed. If any
data remains to be transferred, this protocol is repeated starting from step 3).
(The maximum data size is 8 KB.)
5-172 C141-E254
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