ISD-200 Datasheet, PDF (17/64 Pages) List of Unclassifed Manufacturers – USB Mass Storage Class Bulk-Only Specification Compliant

ISD-200 ASIC Datasheet
Address
Field Name
Description
0x08
Initialization Status –
Bit[7]
This (Read Only) bit denotes the Device Initialization Status. If set, indicates
the device initialization sequence is active.
Configuration
Descriptor 2 Present –
Bit[6]
This bit specifies that a second Configuration Descriptor is present. See
“BUS_POWER pin” under the “Power Management” section.
“0” - not present
“1” - present
Skip ATA / ATAPI
Device Initialization –
Bit[5]
This bit specifies that the ISD-200 skip device initialization.
“0” - normal operation
“1” - only reset the device prior to allowing USB enumeration. The function
of this bit is overridden (0) if I_MODE is set. Notification command,
descriptor override, SRST enable, ATAPI DEVICE RESET settings are
irrelevant.
ATA HIGH POWER
Device for USB Bus
Powered Devices –
Bit[4]
Setting this bit indicates that when USB Bus powered, the system’s ATA
interface is only powered when the NPWR500 pin is active (not controlled by
NPWR100).
“0” – normal operation
“1” – If (BUS_POWER = 1) and (USB configuration = 0) then
ATA pads are put into low power mode,
ATA control lines (RESET-, DIOR-, DIOW-) are 3-stated to hi-Z, and the
remainder of the ATA lines(NCS(1:0), DA(2:0), DD(15:0), and
IORDY_PU_EN) are driven low. (See Power Management section)
Descriptor Override –
Bit[3]
Setting this bit causes the ISD-200 to override the USB Descriptors for ATA
devices. Not compatible with setting BUS_POWER=1.
If set, (I_MODE = 0), AND (ATA device identified or device initialization
fails),
bDeviceClass returned as 0xFF
bDeviceSubClass returned as 0x00
bDeviceProtocol returned as 0xFF
bInterfaceClass returned as 0xFF
bInterfaceSubClass returned as 0x00
bInterfaceProtocol returned as 0xFF
idProduct bit 0 is replaced with a ‘1’
(Suggested: even idProduct for ATAPI devices, odd numbers for
ATA devices)
else
USB descriptor information unaltered
0x09
Last LUN Identifier –
Bits[2:0]
Reserved – Bits[7:2]
This field denotes the (zero-based) maximum number of LUNs supported.
POR configuration default of 0x30
Reserved; set to ‘0’
Report One
Configuration – Bit[1]
This bit determines whether one or two configuration descriptors are made
available to the host. This bit should not be set if the Configuration
Descriptor 2 Present configuration bit is not set.
“0” - Both descriptors are reported to the host if BUS_POWER=0
“1” - Report only the configuration descriptor that corresponds to state of the
BUS_POWER input. Configuration 1 is returned when BUS_POWER=1,
configuration 2 is returned when BUS_POWER=0
SRST Enable – Bit[0]
Setting this bit enables the SRST reset algorithm in the ISD-200.
POR configuration default of 0x00
Table 3 – ISD-200 Configuration Bytes
On-board
Defaults
0x08
0x01
Valid Configuration Byte Settings
The following table depicts valid combinations of configuration byte settings and inputs that depend on the
configuration source and USB Bus power usage. Operation outside the defined values may result in
unexpected behavior and should be avoided.
In-System Design Confidential
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