Datasheet

553
AT32UC3A
30.8.1.10 USB Finite State Machine Status Register (USBFSM)
Offset: 0x082C
Register Name: USBFSM
Access Type: Read-Only
Read Value: 0x00000009
• DRDSTATE
This field indicates the state of the USB controller.
Refer to the OTG specification for more details.
31 30 29 28 27 26 25 24
- - - - - - - -
0 0 0 0 0 0 0 0
23 22 21 20 19 18 17 16
- - - - - - - -
0 0 0 0 0 0 0 0
15 14 13 12 11 10 9 8
- - - - - - - -
0 0 0 0 0 0 0 0
7 6 5 4 3 2 1 0
- - - - DRDSTATE
r
0 0 0 0 1 0 0 1
USBFSM Description
0 a_idle state : this is the start state for A-devices (when the ID pin is 0)
1
a_wait_vrise : In this state, the A-device waits for the voltage on VBus to rise above the A-
device VBus Valid threshold (4.4 V).
2 a_wait_bcon : In this state, the A-device waits for the B-device to signal a connection.
3 a_host : In this state, the A-device that operates in Host mode is operational.
4 a_suspend : The A-device operating as a host is in the suspend mode.
5 a_peripheral : The A-device operates as a peripheral.
6
a_wait_vfall : In this state, the A-device waits for the voltage on VBus to drop below the A-
device Session Valid threshold (1.4 V).
7
a_vbus_err : In this state, the A-device waits for recovery of the overcurrent condition that
caused it to enter this state.
8
a_wait_discharge : In this state, the A-device waits for the data usb line to discharge (100
us).
9 b_idle : this is the start state for B-device (when the ID pin is 1).
10 b_peripheral : In this state, the B-device acts as the peripheral.
32058K
AVR32-01/12