Handling of LowPowerModes | Cypress Semiconductor
Handling of LowPowerModes
I need some clarifications rgd. LowPowerModes of FX3:
1. The CYUSB3014-datasheet describes two different suspend-modes L1 (PHY on) and L2 (PHY off):
- Am I right that both modes set the FX3 to USB3.0 LPM U3?
- How can I enter L1 or L2 using any API in the firmware? The API CyU3PSysEnterSuspendMode() doesn't allow to choose L1 or L2.
- L1 would lead to a higher current-consumption (3.52mA) than allowed by USB3.0-spec (2.5mA)?!
2. Which kind of USB-packets trigger the USB-event CY_U3P_USB_EVENT_SUSPEND?
3. According to FX3APIGuide host-requests to go to LPM U1 and U2 shall be handled by registering a callback-function using CyU3PUsbRegisterLPMRequestCallback(). The callback must return TRUE to accept the host-request and false to reject the request.
- Must the firmware set the device into U1 or U2 using CyU3PUsbSetLinkPowerState() in the callback-function or is it already implemented in the driver? If it's the latter case:
- Can I use the CyU3PUsbSetLinkPowerState() to send a device-request for switching to U1/U2 to the USB-host?