USB Registers
1779
SLAU723A – October 2017 – Revised October 2018
Copyright © 2017–2018, Texas Instruments Incorporated
Universal Serial Bus (USB) Controller
Figure 27-76. USBLPMRIS Register (OTG B / Device)
7
6
5
4
3
2
1
0
RESERVED
ERR
RES
NC
ACK
NY
LPMST
R-0x0
R-0x0
R/W-0x0
R/W-0x0
R/W-0x0
R/W-0x0
R/W-0x0
Table 27-83. USBLPMRIS Register Field Descriptions (OTG B / Device)
Bit
Field
Type
Reset
Description
7-6
RESERVED
R
0x0
5
ERR
R
0x0
LPM Interrupt Status.
0x0 = No status interrupt.
0x1 = An LPM transaction is received that has a Link State field that
is not supported and an interrupt has triggered and is pending. In
this case the response to the transaction is to STALL. However, the
LPMATTR register is updated so that software can observe the non-
compliant LPM packet payload.
4
RES
R/W
0x0
LPM Resume Interrupt Status.
This bit is mutually exclusive from the RESUME bit in the
USBPOWER register (0x001).
0x0 = No status interrupt
0x1 = The USB has been resumed.
3
NC
R/W
0x0
LPM NC Interrupt Status.
This condition can only occur when the LPMEN field is set to 0x3
and the TXLPM field is set to 0x1 in the LPMCNTRL register and
there is no data pending in the USB TX FIFOs.
0x0 = No status interrupt.
0x1 = An LPM transaction has been received and the USB has
responded with a NYET due to a data pending in the RX FIFOs.
2
ACK
R/W
0x0
LPM ACK Interrupt Status.
This condition can only occur when the LPMEN field is set to 0x3
and the TXLPM field is set to 0x1 in the LPMCNTRL register and
there is no data pending in the USB TX FIFOs.
0x0 = No status interrupt.
0x1 = An LPM transaction is received and the USB responds with an
ACK.
1
NY
R/W
0x0
LPM NY Interrupt Status.
This condition can only occur when the LPMEN field is set to 0x3
and the TXLPM field is 0x0 in the LPMCNTRL register.
0x0 = No status interrupt.
0x1 = An LPM transaction is received and the USB has responded
with a NYET.
0
LPMST
R/W
0x0
LPM STALL Interrupt Status.
This condition can only occur if the LPMEN field in the LPMCNTRL
field is set to 0x1.
0x0 = No status interrupt.
0x1 = An LPM transaction is received and the USB has responded
with a STALL.