XR21V1412IL-0A Datasheet, PDF (13/32 Pages) Exar Corporation – 2-CH FULL-SPEED USB UART

XR21V1412
REV. 1.3.0
2-CH FULL-SPEED USB UART
1.5.13 Remote Wakeup
When the V1412 is suspended, the GPIO0/RI#/RWK# pin can be used to request that the host exit the
Suspend state. A high to low transition on this pin will cause the device to signal a remote wakeup request to
the host via a custom driver. Note that the standard CDC-ACM driver does not support this feature. In order for
the remote wakeup to work, several things must be properly configured. First, the GPIO0/RI# pin must be
configured as an input. Additionally, the V1412 device must have the remote wakeup feature support indicated
in the USB attributes - See “Section 1.3, I2C Interface” on page 7. Lastly, the software driver must inform
the USB host that the peripheral device supports the remote wake-up feature.
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