USB Registers
1702
SLAU723A – October 2017 – Revised October 2018
Copyright © 2017–2018, Texas Instruments Incorporated
Universal Serial Bus (USB) Controller
Figure 27-4. USBPOWER Register (OTG B / Device)
7
6
5
4
3
2
1
0
ISOUP
SOFTCONN
HSENAB
HSMODE
RESET
RESUME
SUSPEND
PWRDNPHY
R/W-0x0
R/W-0x0
R/W-0x1
R-0x0
R-0x0
R/W-0x0
R-0x0
R/W-0x0
Table 27-9. USBPOWER Register Field Descriptions (OTG B / Device)
Bit
Field
Type
Reset
Description
7
ISOUP
R/W
0x0
Isochronous Update.
This bit is only valid for isochronous transfers.
0x0 = No effect.
0x1 = The USB controller waits for an SOF token from the time the
TXRDY bit is set in the USBTXCSRLn register before sending the
packet. If an IN token is received before an SOF token, then a zero-
length data packet is sent.
6
SOFTCONN
R/W
0x0
Soft Connect/Disconnect.
0x0 = The USB D+/D- lines are tri-stated.
0x1 = The USB D+/D- lines are enabled.
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 Enable.
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
0x0
RESET Signaling.
0x0 = RESET signaling is not present on the bus.
0x1 = RESET signaling is present on the bus.
2
RESUME
R/W
0x0
RESUME Signaling.
This bit must be cleared by software 10 ms (a maximum of 15 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
0x0
SUSPEND Mode.
0x0 = This bit is cleared when software reads the interrupt register or
sets the RESUME bit above.
0x1 = The USB controller is in SUSPEND mode.
0
PWRDNPHY
R/W
0x0
Power Down PHY.
0x0 = No effect.
0x1 = Powers down the internal USB PHY.