Read Dma Ext (25H); Table 85: Read Dma Ext (25H) - Hitachi IC25N040ATMR04-0 - Travelstar 40GB Laptop Hard Drive 9.5mm 2.5 Inch Notebook HDD Specifications

13.14 Read DMA EXT (25h)

Table 85: Read DMA EXT (25h)

Command Block Output Registers
Register
Data Low
Data High
Current
Feature
Previous
Current
Sector
Count
Previous
Current
LBA Low
Previous
Current
LBA Mid
Previous
Current
LBA High
Previous
Device
Command
Error Register
7 6 5
CRC UNC 0
V V 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 This indicates the number of sectors to be transferred low order, bits (7-0)
Sector Count Previous This indicates the number of sectors to be transferred high order, bits (15-8). If 0000h in
LBA Low Current
LBA Low Previous
LBA Mid Current
LBA Mid Previous
LBA High Current
LBA 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
1 1 1 D - - - -
0 0 1 0 0 1 0 1
4 3 2 1
IDN 0 ABT T0N AMN
V 0 V 0
the Sector Count register is specified, 65.536 sectors will be transferred.
LBA (7-0)
LBA (31-24)
LBA (15-8)
LBA (39-32)
LBA (23-16)
LBA (47-40)
Travelstar 80GN Hard Disk Drive Specification
Command Block Input Registers
Register
Data Low
Data High
Error
HOB=0
Sector
Count
HOB=1
HOB=0
LBA Low
HOB=1
HOB=0
LBA Mid
HOB=1
HOB=0
LBA High
HOB=1
Device
Status
0 7 6 5
BSY RDY DF DSC DRQ
V 0 V 0
126
7 6 5 4 3 2 1 0
- - - - - - - -
- - - - - - - -
see below
- - - - - - - -
- - - - - - - -
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 - - - - - - -
See below ...
Status Register
4 3 2 1
COR IDX
V - 0 -
0
ERR
V