Copyright © 2013 Future Technology Devices International Limited

10

DS_FT312D USB ANDROID HOST IC Datasheet

Version 1.0

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

Logic 1

Device not connected

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