SAM4L Datasheet, PDF (366/1185 Pages) ATMEL Corporation – ATSAM ARM-based Flash MCU

17.7.1 USB General Registers
17.7.1.1
Name:
General Control Register
USBCON
Access Type:
Read/Write
Offset:
0x0800
Reset Value:
0x03004000
ATSAM4L4/L2
31
30
29
28
27
26
25
24
-
-
-
-
-
-
UIMOD
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
15
14
13
12
11
10
9
8
USBE
FRZCLK
-
-
-
-
-
-
7
6
5
4
3
2
1
0
-
-
-
-
-
-
-
-
• UIMOD: USBC Mode
0: The module is in USB host mode.
1: The module is in USB device mode.
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.
• USBE: USBC Enable
Writing a zero to this bit will disable the USBC, USB transceiver, and USB clock inputs. This will over-ride FRZCLK settings but
not affect the value. Unless explicitly stated, all registers will become reset and read-only.
Writing a one to this bit will enable the USBC.
0: The USBC is disabled.
1: The USBC is enabled.
This bit can be written to even if FRZCLK is one.
• FRZCLK: Freeze USB Clock
Writing a zero to this bit will enable USB clock inputs.
Writing a one to this bit will disable USB clock inputs. The resume detection will remain active. Unless explicitly stated, all
registers will become read-only.
0: The clock inputs are enabled.
1: The clock inputs are disabled.
This bit can be written to even if USBE is zero.
42023C–SAM–02/2013
366