ISD-200 Datasheet, PDF (52/64 Pages) List of Unclassifed Manufacturers – USB Mass Storage Class Bulk-Only Specification Compliant

ISD-200 ASIC Datasheet
5. Current draw of 5-6 mA when ATA_EN = 0
The ATA cells are not powered down when ATA_EN is inactive. When enabled, the ATA cell active
circuitry typically draws between 5-6 mA of quiescent current (all cells combined). Disabling the active
circuitry reduces quiescent current to approximately 4 uA (note the inputs must be tied high or low to keep
them out of their high current switching region).
The TEST[3:0] inputs will place the ATA cells in low power mode if used in conjunction with ATA_EN.
Setting TEST[3:0] = “1111” with ATA_EN = 0 will place the ATA cells in low power mode. Quiescent
current will then be approximately 1 mA. This solution is compatible with rev B silicon (although not
required).
6. USB Bus powered system support not possible with ISD-200 first silicon.
There are several issues that prevent the ISD-200 from supporting USB Bus powered systems. These
issues only effect USB Bus powered operation. Brick powered system support is not effected.
ISD-200 rev A silicon can only be used in brick powered systems. The rev B version of the ISD-200 will
address the issues and thus support USB Bus powered system integration.
7. USB Interrupt pipe support required for Mac OS drivers / applications
Although the USB Interrupt endpoint in the ISD-200 always returns 0x00’s when addressed, some software
/ drivers used with Mac OS version expect the endpoint for proper operation. This is not a HW issue with
the ISD-200; it has been implemented as a work-around solution for legacy software issues.
For legacy driver compatibility reasons, the interrupt endpoint should be reported in the ISD-200 USB
descriptor information.
8. Support not provided for 16 byte ATAPI command block transfers
Previous revisions of this data sheet state the ISD-200 can support 16 byte ATAPI command blocks. The
ATAPI Command Block Size configuration bits (configuration byte 0x05, bits[7:6]) must be set to “00”, as
only 12 byte ATAPI command block are supported by the ISD-200.
Advertisement of this feature has been removed from the data sheet. The ISD-200 will not support 16 byte
ATAPI command block sizes. No changes are planned for rev B silicon.
9. CLKN does not get the correct frequency in all cases
See Errata #101
10. Failure to override descriptors for slave device when BSY=0 and DRQ=1.
See Errata #102.
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