Atmel SAM4L Xplained Pro Starter Kit Atmel ATSAM4L-XSTK ATSAM4L-XSTK Data Sheet
Product codes
ATSAM4L-XSTK
384
42023E–SAM–07/2013
ATSAM4L8/L4/L2
17.7.2
USB Device Registers
17.7.2.1
Device General Control Register
Register Name:
UDCON
Access Type:
Read/Write
Offset:
0x0000
Reset Value:
0x00000100
• GNAK: Global NAK
0: Normal mode.
1: A NAK handshake is answered for each USB transaction regardless of the current endpoint memory bank status.
• LS: low-speed mode force
0: The full-speed mode is active.
1: The low-speed mode is active.
This bit can be written to even if USBE is zero or FRZCLK is one. Disabling the USBC (by writing a zero to the USBE bit) does
not reset this bit.
• RMWKUP: Remote wakeup
Writing a zero to this bit has no effect.
Writing a one to this bit will send an upstream resume to the host for a remote wakeup.
This bit is cleared when the USBC receives a USB reset or once the upstream resume has been sent.
• DETACH: Detach
Writing a zero to this bit will reconnect the device.
Writing a one to this bit will physically detach the device (disconnect internal pull-up resistor from DP and DM).
• ADDEN: Address Enable
Writing a zero to this bit has no effect.
Writing a one to this bit will activate the UADD field (USB address).
This bit is cleared when a USB reset is received.
• UADD: USB Address
This field contains the device address.
This field is cleared when a USB reset is received.
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
GNAK
-
15
14
13
12
11
10
9
8
-
-
-
LS
-
-
RMWKUP
DETACH
7
6
5
4
3
2
1
0
ADDEN
UADD