ISD-300A1 Cypress Semiconductor Corp, ISD-300A1 Datasheet - Page 12

• Manufacturer Part Number: ISD-300A1
• Description: IC USB 2.0 BRIDGE BULK 100LQFP
• Manufacturer: Cypress Semiconductor Corp

Specifications of ISD-300A1

• Applications: USB 2.0 to ATA/ATAPI Bridge
• Interface: ATA, ATAPI
• Voltage - Supply: 3 V ~ 3.6 V
• Package / Case: 100-LQFP
• Mounting Type: Surface Mount
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: 428-1459

October 19, 2001
ISD-300A1
Introduction
The ISD-300A1 implements a bridge between one USB port and one ATA or ATAPI based mass storage
device port. This bridge adheres to the Mass Storage Class Bulk-Only Transport specification. Hardware
design allows CBW command queuing, which with vendor specific drivers allows data transfer rates of up
to the USB theoretical maximum.
The USB port of the ISD-300A1 is connected to a host computer directly or via the downstream port of a
USB hub. Host software issues commands and data to the ISD-300A1 and receives status and data from
the ISD-300A1 using standard USB protocol.
The ATA/ATAPI port of the ISD-300A1 is connected to a mass storage device. A large 8 Kbyte buffer
maximizes ATA/ATAPI data transfer rates by minimizing losses due to device seek times. The ATA
interface supports ATA PIO modes 0-4, and Ultra Mode DMA modes 0-4.
The device initialization process is configurable, enabling the ISD-300A1 to initialize most ATA/ATAPI
devices without software intervention. The ISD-300A1 can also be configured to allow software
initialization of a device if initialization requirements are not supported by ISD-300A1 algorithms.
ISD-300A1 Configuration
Certain timing parameters and operational modes are configurable by external configuration data. USB
descriptor information is also retrieved externally. ISD-300A1 configuration data should not be confused
with the USB Configuration Descriptor data.
ISD-300A1 Configuration and USB Descriptor Sources
ISD-300A1 configuration and USB descriptor data can be retrieved from three sources. Table 3 indicates
the method of determining which data source is used.
2
ISD-300A1 configuration and USB descriptor data can be supplied from an I
C serial memory device. The
2
ISD-300A1 can address 2 Kbytes of I
C data, but ISD-300A1 configuration and USB descriptor
2
information are limited to 512 bytes maximum. Unused register space in the I
C serial memory device may
be used for product specific data storage. Note that no descriptor is allowed to span multiple pages within
2
the I
C serial memory device. The ISD-300A1 provides support for the 24LC01-16 EEPROM family.
Alternatively, configuration and descriptor data can be supplied by an attached mass storage device through
a vendor-specific Identify (FBh) ATA command. The ISD-300A1 provides 256 bytes of internal RAM for
FBh data storage.
The ISD-300A1 also contains an internal set of ISD-300A1 configuration and USB descriptors. Retrieval
of internal ROM data will occur under the specific circumstances outlined in Table 3. The internal
descriptors may only be used during manufacturing, as the internal ROM values disable some features
required for normal operation to aid use in a manufacturing environment. NOTE: The internal descriptors
do not provide a unique serial number (required for USB Mass Storage Class compliance), and therefore
2
cannot be used for shipping products. An external I
C memory device or utilization of the vendor specific
FBh identify command is required to correctly configure the ISD-300A1 for operation and provide a
unique serial number for MSC compliance.
7