Specifications

Set D+,D- to Hi-Z;
Disconnect USB
Pullup Resistor
Wait 10 ms
Wait 2 Usec
D+ and
D- Low?
Wait 2 Usec
D+ and
D- Low?
Wait 2 Usec
D+ and
D- Low?
Wait 2 Usec
D+ and
D- Low?
1 ms
expired?
Connect USB Pullup
Resistor
Wait 10 Usec
D- Hi and
D+ Lo?
Interface is PS2
50 Msec
Expired?
Interface is USB
n
y
y
y
y
y
y
n
n
n
y
n
n
n
Disconnect USB
Pullup Resistor
Figure 26. AutoConfigure