Read Multiple Ext [29H] - Hitachi C4K60 - Travelstar Slim - Hard Drive Specifications

7.5.20. Read Multiple EXT [29h]

Task File Register
Command
Feature
LBA High
LBA Mid
LBA Low
Sector Count
Device
The READ MULTIPLE EXT command is similar to the READ SECTORS EXT command, except interrupts
are not generated on every sector, but on the transfer of a block which contains the number of sectors
defined by a SET MULTIPLE MODE command. The number of sectors defined by a SET MULTIPLE MODE
command is transferred without intervening interrupts. DRQ qualification of the transfer is required only at
the start of the data block, not on each sector. The SET MULTIPLE MODE command, which must be
executed prior to the READ MULTIPLE EXT command, sets the block count of sectors to be transferred.
When the READ MULTIPLE EXT command is issued, the Sector Count Register contains the number of
sectors (not the number of blocks or the block count) requested. If the number of requested sectors is not
evenly divisible by the block count, as many full blocks as possible are transferred, followed by a final, partial
block transfer for n sectors, where n = residue of {Sector Count / Sector Count per Block}.
Disk errors encountered during READ MULTIPLE EXT commands are posted at the beginning of the block
or partial block transfer, but DRQ is still set and the data transfer should be executed as it normally would,
including transfer of corrupted data, if any. Subsequent blocks or partial blocks are transferred only if the
error was a correctable data error. All other errors cause the command to stop after transfer of the block that
contained the error. Interrupts are generated when DRQ is set at the beginning of each block or partial block.
K6610170
Rev.2
Dec 22, 2004
Previous setting
Current setting
Previous setting
Current setting
Previous setting
Current setting
Previous setting
Current setting
Previous setting
Current setting
7 6 5
LBA bit 47 - 40
LBA bit 23 - 16
LBA bit 39 - 32
LBA bit 15 - 8
LBA bit 31 - 24
LBA bit 7 - 0
Sector Count bit 15 - 8
Sector Count bit 7 - 0
X 1 X
- 85 -
4 3 2
29h
XX
XX
DEV X X
1 0
X X