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IDE Solid State Disk
(9) Read Sector(s) - 20h or 21h
Bit ->
7
Command (7)
1
C/D/H (6)
Cyl High (5)
Cyl Low (4)
Sec Num (3)
Sec Cnt (2)
Feature (1)
This command reads from 1 to 256 sectors as specified in the Sector Count register. A sector count of 0 requests 256
sectors. The transfer begins at the sector specified in the Sector Number Register. When this command is issued and
after each sector of data (except the last one) has been read by the host, the device sets BSY, puts the sector of data
in the buffer, sets DRQ, clears BSY, and generates an interrupt. The host then reads the 512 bytes of data from the
buffer.
At command completion, the Command Block Registers contain the cylinder, head and sector number of the last
sector read. If an error occurs, the read terminates at the sector where the error occurred. The Command Block
Registers contain the cylinder, head, and sector number of the sector where the error occurred. The flawed data is
pending in the sector buffer.
(10) Read Verify Sector(s) - 40h or 41h
Bit ->
7
Command (7)
1
C/D/H (6)
Cyl High (5)
Cyl Low (4)
Sec Num (3)
Sec Cnt (2)
Feature (1)
This command is identical to the Read Sectors command, except that DRQ is never set and no data is transferred to
the host. When the command is accepted, the device sets BSY.
When the requested sectors have been verified, the device clears BSY and generates an interrupt. Upon command
completion, the Command Block Registers contain the cylinder, head, and sector number of the last sector verified.
If an error occurs, the Read Verify Command terminates at the sector where the error occurs. The Command Block
Registers contain the cylinder, head and sector number of the sector where the error occurred. The Sector Count
Register contains the number of sectors not yet verified.
(11) Recalibrate - 1Xh
Bit ->
7
Command (7)
1
C/D/H (6)
Cyl High (5)
Cyl Low (4)
Sec Num (3)
Sec Cnt (2)
Feature (1)
Rev. A.6
6
5
LBA
1
Cylinder High (LBA 23-16)
Cylinder Low (LBA 15-8)
Sector Number (LBA 7-0)
Read Sector(s)
6
5
LBA
1
Cylinder High (LBA 23-16)
Cylinder Low (LBA 15-8)
Sector Number (LBA 7-0)
Read Verify Sector(s)
6
5
LBA
1
Recalibrate
21/32
4
3
20h or 21h
Drive
Sector Count
X
4
3
40h or 41h
Drive
Sector Count
X
4
3
1Xh
Drive
X
X
X
X
X
2
1
Head (LBA 27-24)
2
1
Head (LBA 27-24)
2
1
X
Nov. 2008
0
0
0
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