USB Registers
1707
SLAU723A – October 2017 – Revised October 2018
Copyright © 2017–2018, Texas Instruments Incorporated
Universal Serial Bus (USB) Controller
27.5.7 USBIS Register (Offset = 0xA) [reset = 0x0]
USB General Interrupt Status (USBIS)
OTG A / Host
OTG B / Device
USBIS is an 8-bit read-only register that indicates which USB interrupts are currently active. All active
interrupts are cleared when this register is read.
USBIS for OTG A / Host is shown in
and described in
.
USBIS for OTG B / Device is shown in
and described in
Return to
Figure 27-9. USBIS Register (OTG A / Host)
7
6
5
4
3
2
1
0
VBUSERR
SESREQ
DISCON
CONN
SOF
BABBLE
RESUME
RESERVED
R-0x0
R-0x0
R-0x0
R-0x0
R-0x0
R-0x0
R-0x0
R-0x0
Table 27-14. USBIS Register Field Descriptions (OTG A / Host)
Bit
Field
Type
Reset
Description
7
VBUSERR
R
0x0
VBUS Error.
0x0 = No interrupt.
0x1 = VBUS has dropped below the VBUS Valid threshold during a
session.
6
SESREQ
R
0x0
SESSION REQUEST.
0x0 = No interrupt.
0x1 = SESSION REQUEST signaling has been detected.
5
DISCON
R
0x0
Session Disconnect.
0x0 = No interrupt.
0x1 = A Device disconnect has been detected.
4
CONN
R
0x0
Session Connect.
0x0 = No interrupt.
0x1 = A Device connection has been detected.
3
SOF
R
0x0
Start of Frame.
0x0 = No interrupt.
0x1 = A new frame has started.
2
BABBLE
R
0x0
Babble Detected.
0x0 = No interrupt.
0x1 = Babble has been detected. This interrupt is active only after
the first SOF has been sent.
1
RESUME
R
0x0
RESUME Signaling Detected.
This interrupt can only be used if the USB controller's system clock
is enabled.
If the user disables the clock programming, the USBDRRIS,
USBDRIM, and USBDRISC registers should be used.
0x0 = No interrupt.
0x1 = RESUME signaling has been detected on the bus while the
USB controller is in SUSPEND mode.
0
RESERVED
R
0x0