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Revision 1.6
Nov. 16, 2000
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GL620USB
4. Functional Description
Block diagram of GL620USB-Lite
The GL620USB-Lite is equipped with two full-speed USB ports, and each port has four endpoints to provide
different functions as follows:
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Endpoint 0: control transfer
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Endpoint 1: bulk-read transfer
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Endpoint 2: bulk-write transfer
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Endpoint 3: interrupt transfer
Two 8-bytes FIFO and four 64-bytes FIFO are built in the device as follows:
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Left 8-byte FIFO: provide a pipe to link left endpoint 0 and right endpoint 3. For example, if left host wants
to communicate with right host, left host can issue a no data control transfer and the setup command will be stored
64 Byte FIFO
64 Byte FIFO
8 Byte FIFO
8 Bytes FIFO
USB
Interface
USB
Interface
Micro-
controller
USB Registers
&
FIFO Control
D+
D-
D+
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