Read Dma Ext (25H); Table 42. Read Dma Ext Command (25H) - Hitachi Deskstar 7K500 Specifications

5.16 Read DMA Ext (25h)

Table 42: 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 Vs 0
The Read DMA command reads one or more sectors of data from disk media, then transfers the data from the
device to the host.
The sectors are transferred through the Data Register 16 bits at a time.
The host initializes a slave-DMA channel prior to issuing the command. The data transfers are qualified by
DMARQ and are performed by the slave-DMA channel. The device issues only one interrupt per command to indi-
cate that data transfer has terminated and status is available.
If an uncorrectable error occurs, the read will be terminated at the failing sector.
Output parameters to the device
Sector Count Current
Sector Count Previous
Sector Number Current
Sector Number Previous
Cylinder Low Current
Cylinder Low 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
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
Sector Count register is specified, then 65,536 sectors will be transferred.
LBA (7:0)
LBA (31:24)
LBA (15:8)
LBA (39:32)
Deskstar 7K500 Hard Disk Drive Serial ATA Addendum
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
78
7 6 5 4 3 2 1 0
- - - - - - - -
- - - - - - - -
see below
HOB=0 - - - - - - - -
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