USB Registers
1716
SLAU723A – October 2017 – Revised October 2018
Copyright © 2017–2018, Texas Instruments Incorporated
Universal Serial Bus (USB) Controller
27.5.13 USBDEVCTL Register (Offset = 0x60) [reset = 0x80]
USB Device Control (USBDEVCTL)
OTG A / Host
USBDEVCTL is an 8-bit register used for controlling and monitoring the USB VBUS line. If the PHY is
suspended, no PHY clock is received and the VBUS is not sampled. In addition, in Host mode,
USBDEVCTL provides the status information for the current operating mode (Host or Device) of the USB
controller. If the USB controller is in Host mode, this register also indicates if a full- or low-speed Device
has been connected.
USBDEVCTL is shown in
and described in
.
Return to
Figure 27-18. USBDEVCTL Register
7
6
5
4
3
2
1
0
DEV
FSDEV
LSDEV
VBUS
HOST
HOSTREQ
SESSION
R-0x1
R-0x0
R-0x0
R-0x0
R-0x0
R/W-0x0
R/W-0x0
Table 27-23. USBDEVCTL Register Field Descriptions
Bit
Field
Type
Reset
Description
7
DEV
R
0x1
Device Mode.
This value is only valid while a session is in progress.
0x0 = The USB controller is operating on the OTG A side of the
cable.
0x1 = The USB controller is operating on the OTG B side of the
cable.
6
FSDEV
R
0x0
Full-Speed Device Detected.
0x0 = A full-speed Device has not been detected on the port.
0x1 = A full-speed Device has been detected on the port.
5
LSDEV
R
0x0
Low-Speed Device Detected.
0x0 = A low-speed Device has not been detected on the port.
0x1 = A low-speed Device has been detected on the port.
4-3
VBUS
R
0x0
VBUS Level.
0x0 = Below SessionEnd
VBUS is detected as under 0.5 V.
0x1 = Above SessionEnd, below AValid
VBUS is detected as above 0.5 V and under 1.5 V.
0x2 = Above AValid, below VBUSValid
VBUS is detected as above 1.5 V and below 4.75 V.
0x3 = Above VBUSValid
VBUS is detected as above 4.75 V.
2
HOST
R
0x0
Host Mode.
This value is only valid while a session is in progress.
0x0 = The USB controller is acting as a Device.
0x1 = The USB controller is acting as a Host.
1
HOSTREQ
R/W
0x0
Host Request.
This bit is cleared when Host Negotiation is completed.
0x0 = No effect.
0x1 = Initiates the Host Negotiation when SUSPEND mode is
entered.
0
SESSION
R/W
0x0
Session Start/End.
When operating as an OTG A device: When operating as an
OTG B device:
Clearing this bit when the USB controller is not
suspended results in undefined behavior.
0x0 = When cleared by software, this bit ends a session.
0x1 = When set by software, this bit starts a session.