Universal Serial Bus OTG Controller
UG0331 User Guide Revision 15.0
367
10.3.14.4 LPM_CTRL_REG (Host) Bit Definitions
10.3.14.5 LMP_INTR_EN_REG Bit Definitions
0
LPMXMT 0
Instructs the USB controller to transition to the L1 state upon the receipt of the next
LPM transaction. This bit is only effective if LPMEN (bits[3:2] of this register) is set to
11. This bit can be set in the same cycle as LPMEN. If this bit is set to 1 and LPMEN =
11, the USB controller can respond in the following ways:
If any data is not pending (all transmit FIFOs are empty), the USB controller will
respond with an ACK. In this case this bit will self clear and a software interrupt will be
generated.
If any data is pending (data resides in at least one transmit FIFO), the USB controller
will respond with a NYET. In this case, this bit will NOT self clear; however, a software
interrupt will be generated.
Table 307 •
LPM_CTRL_REG (0x40043362) (Host)
Bit
Number Name
Reset
Value Function
[7:2]
Reserved
N/A
1
LPMRES
0
Initiates a RESUME from the L1 state. This bit differs from the classic RESUME bit
(POWER_REG.bit2) in that the RESUME signal timing is controlled by hardware.
When software writes this bit, resume signaling is asserted for a time specified by the
HIRD field (LPM_ATTR_REG.bit[7:4]). This bit is self clearing.
0
LPMXMT
0
Transmits an LPM transaction. This bit is self clearing. This bit will be immediately
cleared upon receipt of any token or three timeouts have occurred.
Table 308 •
LPM_INTR_EN_REG (0x40043363)
Bit
Number Name
Reset
Value
Function
[7:6]
Reserved
N/A
5
LPMERREN 0
0: Disable the LPMERR interrupt
1: Enable the LPMERR interrupt
4
LPMRESEN 0
0: Disable the LPMRES interrupt
1: Enable the LPMRES interrupt
3
LPMNCEN
0
0: Disable the LPMNC interrupt
1: Enable the LPMNC interrupt
2
LPMACKEN 0
0: Disable the LPMACK interrupt
1: Enable the LPMACK interrupt
1
LPMNYEN
0
0: Disable the LPMNY interrupt
1: Enable the LPMNY interrupt
0
LPMSTEN
0
0: Disable the LPMST interrupt
1: Enable the LPMST interrupt
Table 306 •
LPM_CTRL_REG (0x40043362)(Peripheral)
(continued)
Bit
Number
Name
Reset
Value Function