User guide

203 Series Industrial Grade 2.5" FlashDrive Product Manual v2.0Cactus Technologies
®
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5.1.9. Read Buer-E4H
Table 5-20. Read Buer
Bit -> 7 6 5 4 3 2 1 0
Command (7)
E4H
C/D/H (6)
X Drive X
Cyl High (5)
X
Cyl Low (4)
X
Sec Num (3)
X
Sec Cnt (2)
X
Feature (1)
X
The Read Buer command in Table 5-20 enables the host to read the current contents of the
FlashDrive's sector buer. This command has the same protocol as the Read Sector(s) command.
5.1.10. Read Multiple-C4H
Bit -> 7 6 5 4 3 2 1 0
Command (7)
C4H
C/D/H (6)
1 LBA 1 Drive Head (LBA 27-24)
Cyl High (5)
Cylinder High (LBA 23-16)
Cyl Low (4)
Cylinder Low (LBA 15-8)
Sec Num (3)
Sector Number (LBA 7-0)
Sec Cnt (2)
Sector Count
Feature (1)
X
Table 5-21. Read Multiple
The Read Multiple command in Table 5-21 performs similarly to the Read Sectors command.
Interrupts are not generated on every sector, but on the transfer of a block, which contains the
number of sectors dened by a Set Multiple, command.
Command execution is identical to the Read Sectors operation except that the number of sectors
dened by a Set Multiple command is transferred without intervening interrupts. DRQ qualication
of the transfer is required only at the start of the data block, not on each sector.
The block count of sectors to be transferred without intervening interrupts is programmed by the
Set Multiple Mode command, which must be executed prior to the Read Multiple command. When
the Read Multiple 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 nal,
partial block transfer. The partial block transfer is for n sectors, where:
n = (sector count)—module (block count).
If the Read Multiple command is attempted before the Set Multiple Mode command has been
executed or when Read Multiple commands are disabled, the Read Multiple operation is rejected
with an Aborted Command error. Disk errors encountered during Read Multiple commands are
posted at the beginning of the block or partial block transfer, but DRQ is still set and the data
transfer will take place as it normally would, including transfer of corrupted data, if any.