USB AMR interface (using Audio Class)

For the icebreaker, the USB hardware connections are :

P1B4: USB DP
P1B3: USB DN
P1B2: Pull up. Resistor of 1.5 kOhm to USB DP

and the AMR connections are :

P1A1 : AC97_RESET#
P1A7 : AC97_SDATA_OUT
P1A8 : AC97_SDATA_IN
P1A9 : AC97_SYNC
P1A10 : AC97_BITCLK