Read Dma Queued Ext (26H); Table 104. Read Dma Ext Command (25H) - Hitachi 7K400 - Deskstar Hard Drive Specifications

12.19 Read DMA Queued Ext (26h)

Table 105: Read DMA Ext Command (25h)
Command Block Output Registers
Register
Data Low
Data High
Feature Current
Previous
Sector Current
Count
Previous
Sector Current
Number
Previous
Cylinder Current
Low
Previous
Cylinder Current
High
Previous
Device/Head
Command
7 6 5
CRC UNC 0
V V 0
This command executes in a similar manner to a READ DMA command. The device may perform a bus release or
it may execute the data transfer without performing a bus release if the data is ready to transfer.
If the device performs a bus release, the host shall re-select the device using the SERVICE command.
When the data transfer is begun, the device does not perform a bus release until the entire data transfer has been
completed.
Output parameters to the device
Feature Current
Feature Previous
Sector Count Current
Sector Number Current
Sector Number Previous
Cylinder Low Current
Cylinder Low Previous
Cylinder High Current
Cylinder High Previous
7 6 5 4 3 2 1 0
- - - - - - - -
- - - - - - - -
V V V V V V V V
V V V V V V V V
V V V V - - - -
- - - - - - - -
V V V V V V V V
V V V V V V V V
V V V V V V V V
V V V V V V V V
V V V V V V V V
V V V V V V V V
1 1 1 0 - - - -
0 0 1 0 0 1 0 1
Error Register
4 3 2 1
IDN 0 ABT T0N AMN
V 0 V 0
The number of sectors to be transferred low order, bits (7:0).
The number of sectors to be transferred high order, bits (15:8). If 0000h in the
Feature register is specified, then 65,536 sectors will be transferred.
Bits (7:3) (Tag) contain the Tag for the command being delivered.
LBA (7:0)
LBA (31:24)
LBA (15:8)
LBA (39:32)
LBA (23:16)
LBA (47:40)
Deskstar 7K400 Hard Disk Drive Specification
Command Block Input Registers
Register
Data Low
Data High
Error
Sector
Count
Sector
Number
Cylinder
Low
Cylinder
High
Device/Head
Status
0 7 6
BSY RDY DF DSC DRQ
0 0 V
148
7 6 5 4 3 2 1 0
- - - - - - - -
- - - - - - - -
see below
HOB=0 V V V V V V V V
HOB=1 - - - - - - - -
HOB=0 V V V V V V V V
HOB=1 V V V V V V V V
HOB=0 V V V V V V V V
HOB=1 V V V V V V V V
HOB=0 V V V V V V V V
HOB=1 V V V V V V V V
- - - - - - - -
See below ...
Status Register
5 4 3 2
COR IDX
0 V - 0
1 0
ERR
- V