ISD-200 Datasheet, PDF (35/64 Pages) List of Unclassifed Manufacturers – USB Mass Storage Class Bulk-Only Specification Compliant

ISD-200 ASIC Datasheet
ATA Command Flow
The following figure shows the flow of ATA commands, specifically the actions taken by the ISD-200
based upon how the ATA Command Block is configured.
page 1 of 2
Command Fail OR other command
no
block specification assumed
wATACB
Signature
detected
yes
set
ATACB
PollAltStat
Override
Latch bmATACBActionSelect
Latch bmATACBRegisterSelect
clear
Poll ATA Alternate Status until
BSY=0 and store ERR and DRQ
bits.
Read registers selected in
bmATACBRegisterSelect.
set
ATACB
TaskFileRead
clear
Set TransferLength =
dCBWDataTransferLength
Latch TransferBlockSize
DONE
ATACB
DeviceSelection
set
Override
clear
Perform ATA Device Selection.
The device shall specify the value for the
Note: Only ATA registers
DEV bit.
selected in
bmATACBRegisterSelect are
read. ATA registers not read
are zero filled in the 8 bytes of
returned data.
Write ATA registers selected in
bmATACBRegisterSelect with the
bATACBTaskFileWriteData
dCBWDataTransferLength
must be set to 8.
C
Note: If no ATA registers are
selected then no ATA registers
are written. The device shall
specify the value for the DEV
bit when writing the
DEVICE_HEAD register.
set
B
ATACB
PollAltStat
Override
clear
Poll ATA Alternate Status until
BSY=0 and store ERR and
DRQ bits.
A
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