Datasheet

908
32117D–AVR-01/12
AT32UC3C
32.7.1.2 General Status Register
Register Name: USBSTA
Access Type: Read-Only
Offset: 0x0804
Reset Value: 0x00000000
• CLKUSABLE: Generic Clock Usable
This bit is cleared when the USB generic clock is not usable.
This bit is set when the USB generic clock (that should be 48 Mhz) is usable.
• SPEED: Speed Status
This field is set according to the controller speed mode.
• VBUS: VBUS Level
This bit is cleared when the VBUS line level is low, even if USBE is zero.
This bit is set when the VBUS line level is high, even if USBE is zero.
This bit can be used in device mode to monitor the USB bus connection state of the application.
• ID: USB_ID Pin state
This bit is cleared when the USB_ID level is low, even if USBE is zero.
This bit is set when the USB_ID level is high, even if USBE is zero.
• VBUSRQ: VBUS Request
0: The USB_VBOF output pin is driven low to disable the VBUS power supply generation.
1: The USB_VBOF output pin is driven high to enable the VBUS power supply generation.
This bit is cleared when USBSTACLR.VBUSRQC is written to one or when a VBUS error occurs while VBUSHWC is zero.
This bit is set when USBSTASET.VBUSRQS is written to one.
This bit should only be used in host mode.
31 30 29 28 27 26 25 24
--------
23 22 21 20 19 18 17 16
--------
15 14 13 12 11 10 9 8
- CLKUSABLE SPEED VBUS ID VBUSRQ -
76543210
STOI HNPERRI ROLEEXI BCERRI VBERRI SRPI VBUSTI IDTI
SPEED Speed Status
00 full-speed mode
01 Reserved
10 low-speed mode
11 Reserved