DS_FT312D USB ANDROID HOST IC Datasheet
Version 1.1
Document No.: FT_000816 Clearance No.: FTDI# 331
6 USB Error Detection
Pin 32 of the device is provided to indicate a problem has occurred with the USB connection. The errors
are USB device not supported, USB hub not supported and USB device not responding. USB device not
supported would occur if the USB port was connected to a non-Android class device port. e.g. The
FT312D is not designed to host memory sticks or printers etc. USB hub not supported would be reported
if FT312D is connected to a USB hub. USB device not responding would occur if the USB device connected
to the FT312D host port did not respond and the enumeration failed. The signal states are as follows:
Pin state
Definition
Logic 0
Device connected to USB and functional
Device not connected
Logic 1
One 50ms logic 0 pulse
Device not responding. This pulse occurs at plug-in
and then the signal returns to logic 1. This then
repeats every second.
Two 50ms logic 0 pulses
Device not supported. These pulses occur at plug-
in and then the signal returns to logic 1. This then
repeats every second.
Three 50ms logic 0 pulses
Hub not supported. These pulses occur at plug-in
and then the signal returns to logic 1. This then
repeats every second.
Table 6.1 Error Detection
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