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USB Registers
1701
SLAU723A – October 2017 – Revised October 2018
Copyright © 2017–2018, Texas Instruments Incorporated
Universal Serial Bus (USB) Controller
27.5.2 USBPOWER Register (Offset = 0x1) [reset = 0xA0]
USB Power (USBPOWER)
OTG A / Host
OTG B / Device
USBPOWER is an 8-bit register used for controlling SUSPEND and RESUME signaling and some basic
operational aspects of the USB controller.
USBPOWER for OTG A / Host is shown in
and described in
.
USBPOWER for OTG B / Device is shown in
and described in
.
Return to
Figure 27-3. USBPOWER Register (OTG A / Host)
7
6
5
4
3
2
1
0
RESERVED
HSENAB
HSMODE
RESET
RESUME
SUSPEND
PWRDNPHY
R-0x2
R/W-0x1
R-0x0
R/W-0x0
R/W-0x0
R/W1S-0x0
R/W-0x0
Table 27-8. USBPOWER Register Field Descriptions (OTG A / Host)
Bit
Field
Type
Reset
Description
7-6
RESERVED
R
0x2
5
HSENAB
R/W
0x1
High Speed Enable.
0x0 = The USB operates in full-speed mode.
0x1 = The USB negotiates for high-speed mode when the device is
reset by the hub.
4
HSMODE
R
0x0
High Speed Mode.
This bit becomes valid when the RESET bit (bit 3) is cleared.
Allowance is made for Tiny-J signaling in determining the transfer
speed to select.
0x0 = The USB operates in full-speed mode.
0x1 = USB reset has completed, and the high-speed mode has been
successfully negotiated.
3
RESET
R/W
0x0
RESET Signaling.
0x0 = Ends RESET signaling on the bus.
0x1 = Enables RESET signaling on the bus.
2
RESUME
R/W
0x0
RESUME Signaling.
This bit must be cleared by software 20 ms after being set.
0x0 = Ends RESUME signaling on the bus.
0x1 = Enables RESUME signaling when the Device is in SUSPEND
mode.
1
SUSPEND
R/W1S
0x0
SUSPEND Mode.
0x0 = No effect.
0x1 = Enables SUSPEND mode.
0
PWRDNPHY
R/W
0x0
Power Down PHY.
0x0 = No effect.
0x1 = Powers down the internal USB PHY.