ISD-200 Datasheet, PDF (21/64 Pages) List of Unclassifed Manufacturers – USB Mass Storage Class Bulk-Only Specification Compliant

ISD-200 ASIC Datasheet
Legal values for wValue are as follows:
0x0000
0x0001
0x0002
0x0003
Configuration bytes, addresses 0x2 – 0x9 only
Internal on-board ROM
External serial ROM
Vendor-specific Identify (FBh) data
Illegal values for wValue will result in a STALL condition on the USB port. Attempted reads from a serial
ROM when none is connected or attempted reads from FBh data when not in I_MODE or when a serial
ROM is present will result in a STALL condition. Attempts to read configuration bytes outside the address
space 0x2 – 0x9 will also result in a STALL condition.
SOFT_RESET
This request resets the ISD-200 data path control state machines, buffer ram and the command queue. The
attached device does not get reset.
This USB request is required for error recovery if complex command queuing is used.
CMD_QUEUING_CONTROL
This request sets the type of command queuing used by the ISD-200. Enabling command queuing allows
the ISD-200 to accept a CBW (refer to the USB Mass Storage Class Bulk Only Transport Specification)
from a new command before the CSW for an earlier command has been sent. There are two types of
command queuing, simple command queuing and complex command queuing.
Simple command queuing allows the ISD-200 to accept a CBW for a new command before the previous
command completes. If the previous command is a bulk out transfer, the CBW is not taken until all data
for the previous command has been transferred. The new command will not be operated on until the CSW
for the prior command has been sent. Error recovery is done through a HARD_RESET request.
Complex command queuing enables out of order error recovery without resetting the attached device.
Command queuing is done in the same manner as in simple command queuing. However, in the event of a
an error, the ISD-200 can now accept a SOFT_RESET which resets the ISD-200 but does not reset the
device.
Legal values for wIndex are as follows:
0x0000
0x0001
Simple Command Queuing (POR default)
Complex Command Queuing
Descriptors
Supported Descriptors
• Device
• Configuration
The ISD-200 supports one or two possible configurations depending on the mode of operation.
See Power Management, BUS_POWER pin section.
Configuration 1. This configuration descriptor is used for Self, USB Bus, or Dynamic power
applications. “Dynamic” power is defined to mean that the ISD-200 can operate as Self
or USB Bus powered. The maximum power that can be drawn from the USB Bus is
specified in the bMaxPower descriptor field.
In-System Design Confidential
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