Deskstar T7K500 Hard Disk Drive Specification
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12.26 Read Stream PIO (2Bh)
Table 115: Read Stream PIO (2Bh)
The Read Stream DMA command reads one to 65536 sectors as specified in the Sector Count register. A value of
0000h in the Sector Count register requests 65536 sectors.
The RC bit indicates that the drive operate in a continuous read mode for the Read Stream command. When RC is
cleared to zero the drive shall operate in normal Streaming read mode.
When the Read Continuous mode is enabled, the device shall transfer data of the requested length without setting
the ERR bit. The SE bit shall be set to one if the data transferred includes errors. The data may be erroneous in this
case.
If the Read Continuous bit is set to one, the device shall not stop execution of the command due to errors. If the RC
bit is set to one and errors occur in reading or transfer of the data, the device shall continue to transfer the amount
of data requested and then provide ending status with the BSY bit cleared to zero, the SE bit set to one, the ERR bit
cleared to zero, and the type of error, ICRC,UNC,IDNF, or ABRT, reported in the error log. If the RC bit is set to
one and the Command Completion Time Limit expires, the device shall stop execution of the command and pro-
vide ending status with BSY bit cleared to zero, the SE bit set to one, the ERR bit cleared to zero, and report the
fact that the Command Completion Time Limit expired by setting the CCTO bit in the error log to one, In all cases,
Command Block Output Registers Command Block Input Registers
Register 7 6 5 4 3 2 1 0 Register 7 6 5 4 3 2 1 0
Data Low - - - - - - - - Data Low - - - - - - - -
Data High - - - - - - - - Data High - - - - - - - -
Feature
Current V V V - V V V V
Error see below
Previous V V V V V V V V
Sector
Count
Current V V V V V V V V
Sector
Count
HOB=0 - - - - - - - -
Previous V V V V V V V V HOB=1 - - - - - - - -
Sector
Number
Current V V V V V V V V
Sector
Number
HOB=0 V V V V V V V V
Previous V V V V V V V V HOB=1 V V V V V V V V
Cylinder
Low
Current V V V V V V V V
Cylinder
Low
HOB=0 V V V V V V V V
Previous V V V V V V V V HOB=1 V V V V V V V V
Cylinder
High
Current V V V V V V V V Cylinder
High
HOB=0 V V V V V V V V
Previous V V V V V V V V HOB=1 V V V V V V V V
Device/Head 1 1 1 D - - - - Device/Head - - - - - - - -
Command 0 0 1 0 0 1 0 0 Status See below ...
Error Register Status Register
7654321 0 76543 21 0
CRC UNC 0 IDN 0 ABT T0N AMN BSY RDY DF DSC DRQ COR IDX ERR
VV0V0V0 V 0VVV- 0- V