at91sam9g20-cu ATMEL Corporation, at91sam9g20-cu Datasheet - Page 706

• Manufacturer Part Number: at91sam9g20-cu
• Description: At91 Arm Thumb Microcontrollers
• Manufacturer: ATMEL Corporation

37.6.12
Register Name:UDP_TXVC
Access Type: Read-write
WARNING: The UDP peripheral clock in the Power Management Controller (PMC) must be enabled before any read/write
operations to the UDP registers including the UDP_TXVC register.
• TXVDIS: Transceiver Disable
When UDP is disabled, power consumption can be reduced significantly by disabling the embedded transceiver. This can
be done by setting TXVDIS field.
To enable the transceiver, TXVDIS must be cleared.
• PUON: Pullup On
0: The 1.5KΩ integrated pullup on DP is disconnected.
1: The 1.5 KΩ integrated pullup on DP is connected.
NOTE: If the USB pullup is not connected on DP, the user should not write in any UDP register other than the UDP_TXVC
register. This is because if DP and DM are floating at 0, or pulled down, then SE0 is received by the device with the conse-
quence of a USB Reset.
706
31
23
15
–
–
–
7
–
AT91SAM9G20 Preliminary
UDP Transceiver Control Register
30
22
14
–
–
–
6
–
29
21
13
–
–
–
5
–
28
20
12
–
–
–
4
–
27
19
11
–
–
–
3
–
26
18
10
–
–
–
2
–
PUON
25
17
–
–
9
1
–
6384B–ATARM–15-Dec-08
TXVDIS
24
16
–
–
8
0
–