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USB Protocol Engine -
The USB Protocol Engine manages the data stream from the device USB control endpoint. It
handles the low level USB protocol (Chapter 9) requests generated by the USB host controller and the commands for
controlling the functional parameters of the FIFO.
FIFO TX Buffer (128 byte) -
Data written into the FIFO using the WR pin is stored in the FIFO TX (transmit) Buffer.
The USB host controller removes data from the FIFO TX Buffer by sending a USB request for data from the device
data In endpoint.
FIFO RX Buffer (256 byte) -
Data sent from the USB host controller to the FIFO via the USB data Out endpoint is
stored in the FIFO RX (receive) buffer and is removed from the buffer by reading the contents of the FIFO using the
RD# pin.
FIFO Controller -
The FIFO controller handles the transfer of data between the external FIFO interface pins (D0 - D7)
and the FIFO transmit and receive buffers. A new feature, which is enabled in the internal EEPROM allows high signal
drive strength on the FIFO parallel data bus and handshake control pins.
RESET Generator -
The integrated Reset Generator Cell provides a reliable power-on reset to the device internal
circuitry on power up. A RESET# input is provided to allow other devices to reset the FT245R. RESET# can be tied
to VCCIO or left unconnected, unless there is a requirement to reset the FT245R device from external logic or an
external reset generator I.C.
Internal EEPROM -
The internal EEPROM in the FT245R can be used to store USB Vendor ID (VID), Product ID
(PID), device serial number, product description string, and various other USB configuration descriptors. The device is
supplied with the internal EEPROM settings preprogrammed as described in
FT245R USB UART I.C. Datasheet Version 1.05
© Future Technology Devices International Ltd. 2005
FTDI [ FUTURE TECHNOLOGY DEVICES INTERNATIONAL LTD. ]
