What are the functionalities of the Suspend and Wakeup pins in the USB to UART Bridge Controller?
According to the USB Specification, a downstream device enters a low-power state (consumes less than 2.5 mA) when you set a suspend condition on the D+ or D- pair. An active LOW on Suspend (pin 3) indicates that the USB is in Suspend mode. You can use this to place the CY7C64225 and other external devices in low-power mode.
The device can resume normal operations when the USB detects activity or a reset signal. When the device is in Suspend, and Remote wakeup is enabled, then asserting the wakeup signal generates remote wakeup signaling on the upstream. The device resumes normal operations when the host acknowledges the signal.