Copyright © 2013 Future Technology Devices International Limited

20

DS_FT311D

USB ANDROID HOST IC Datasheet

Version 1.2

Document No.: FT_000660 Clearance No.: FTDI# 305

6 USB Error Detection

Pin 32 (IOBUS7) of the device is provided to indicate a problem has occurred with the USB connection.

Typical errors include USB Device Not Supported, which would occur if the USB port was connected to a

non-Android class device port e.g. the FT311D is not designed to host memory sticks or printers etc. USB

Device Not Responding and Hub not supported would be reported also if connected to a hub. 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 at a 1 second interval.

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 at a 1 second interval.

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 at a 1 second interval.

Table 6.1 Error Detection