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IDE Solid State Disk
msec) is different from the ATA specification.
(5) Idle Immediate - 95h or E1h
Bit ->
7
Command (7)
C/D/H (6)
Cyl High (5)
Cyl Low (4)
Sec Num (3)
Sec Cnt (2)
Feature (1)
This command causes the device to set BSY, enter the Idle mode, clear BSY and generate an interrupt.
(6) Initialize Drive Parameters - 91h
Bit ->
7
Command (7)
X
C/D/H (6)
Cyl High (5)
Cyl Low (4)
Sec Num (3)
Sec Cnt (2)
Feature (1)
This command enables the host to set the number of sectors per track and the number of heads per cylinder. Only the
Sector Count and the Card/Drive/Head registers are used by this command.
(7) Read DMA – C8h
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 uses DMA mode to read 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 the device sets BSY, puts all or part of the sector of data in the buffer. The Card is then permitted,
although not required, to set DRQ, clear BSY. The Card asserts DMAREQ while data is available to be transferred.
The Card asserts DMAREQ while data is available to be transferred. The host then reads the (512 * sector-count)
bytes of data from the Card using DMA. While DMAREQ is asserted by the Card, the Host asserts -DMACK while it is
ready to transfer data by DMA and asserts -IORD once for each 16 bit word to be transferred to the Host.
Interrupts are not generated on every sector, but upon completion of the transfer of the entire number of sectors to be
transferred or upon the occurrence of an unrecoverable error.
At command completion, the Command Block Registers contain the cylinder, head and sector number of the last
Rev. A.6
6
5
X
Idle Immediate
6
5
0
X
Initialize Drive Parameters
6
5
LBA
1
Cylinder High (LBA 23-16)
Cylinder Low (LBA 15-8)
Sector Number (LBA 7-0)
Read DMA
19/32
4
3
95h or E1h
Drive
X
X
X
X
X
3
4
91h
Max Head (no. of heads-1)
Drive
X
X
X
Number of Sectors
X
4
3
C8h
Drive
Sector Count
X
2
1
X
2
1
2
1
Head (LBA 27-24)
Nov. 2008
0
0
0
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