Register Descriptions
1311
SPRUH22I – April 2012 – Revised November 2019
Copyright © 2012–2019, Texas Instruments Incorporated
M3 Universal Serial Bus (USB) Controller
18.5.7 USB General Interrupt Status Register (USBIS), offset 0x00A
NOTE:
Use caution when reading this register. Performing a read may change bit status.
The USB general interrupt status 8-bit read-only register (USBIS) indicates which USB interrupts are
currently active. All active interrupts are cleared when this register is read.
Mode(s):
OTG A or Host
OTG B or Device
USBIS in OTG A/Host Mode is shown in
and described in
.
Figure 18-9. USB General Interrupt Status Register (USBIS) in OTG A/Host Mode
7
6
5
4
3
2
1
0
VBUSERR
SESREQ
DISCON
CONN
SOF
BABBLE
RESUME
Reserved
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
LEGEND: R/W = Read/Write; R = Read only; -
n
= value after reset
Table 18-12. USB General Interrupt Status Register (USBIS) in OTG A/Host Mode Field Descriptions
Bit
Field
Value
Description
7
VBUSERR
VBUS Error
0
No interrupt
1
VBUS has dropped below the VBUS Valid threshold during a session.
6
SESREQ
Session Request
0
No interrupt
1
SESSION REQUEST signaling has been detected.
5
DISCON
Session Disconnect
0
No interrupt
1
A Device disconnect has been detected.
4
CONN
Session Connect
0
No interrupt
1
A Device connection has been detected.
3
SOF
Start of Frame
0
No interrupt
1
A new frame has started.
2
BABBLE
Babble Detected
0
No interrupt
1
Babble has been detected. This interrupt is active only after the first SOF has been sent.
1
RESUME
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.
0
No effect
1
RESUME signaling has been detected on the bus while the USB controller is in SUSPEND mode.
0
Reserved
0
Reserved