R01UH0823EJ0100 Rev.1.00
Page 860 of 1823
Jul 31, 2019
RX23W Group
32. USB 2.0 Host/Function Module (USBc)
RWUPE Bit (Wakeup Detection Enable)
The RWUPE bit enables or disables the downstream port peripheral device to use the remote wakeup function (resume
signal output) when the host controller is selected.
With this bit set to 1, on detecting the remote wakeup signal, the USB detects the resume signal (K-state for 2.5 μs) from
the downstream port device and performs the resume processing (drives the port to the K-state).
With this bit set to 0, the USB ignores the detected remote wakeup signal (K-state) from the peripheral device connected
to the USB port.
While the RWUPE bit is 1, the internal clock should not be stopped even in the suspended state (SYSCFG.SCKE bit
should be set to 1).
This bit should be set to 0 if the function controller is selected.
The WKUP bit enables or disables outputting the remote wakeup signal (resume signal) to the USB bus when the
function controller is selected.
The USB controls the output time of a remote wakeup signal. When this bit is set to 1, the USB sets this bit to 0 after
outputting the 10-ms K-state.
According to USB Specification 2.0, the USB bus idle state must be kept for 5 ms or longer before a remote wakeup
signal is sent. If the USB writes 1 to this bit right after detection of the suspended state, the K-state will be output after
2 ms.
Do not write 1 to this bit, unless the device state is in the suspended state (INTSTS0.DVSQ[2:0] flags = 1xxb) and the
USB host enables the remote wakeup signal. When this bit is set to 1, the internal clock must not be stopped even in the
suspended state (write 1 to this bit while the SYSCFG.SCKE bit = 1).
This bit should be set to 0 if the host controller is selected.
HNPBTOA Bit (Host Negotiation Protocol (HNP) Control)
The HNPBTOA bit is used when switching from device B to device A while in OTG mode. If the HNPBTOA bit is 1, the
internal function control keeps the suspended state until the HNP processing ends even though the SYSCFG.DPRPU bit
= 0 or SYSCFG.DCFM = 1 is set. Even if the falling edge of the D+ signal is detected at this time, no resume (RESM)
interrupt is generated.
After this bit is set to 1, write 0 to this bit by software to terminate the HNP processing when connection to the host (pull-
up on the target side) or timeout of the HNP processing is detected.