Testing USB Host and USB OTG examples of FX3 SDK – KBA232813
Community Translation: FX3 SDK の USB ホストと USB OTG の例のテスト - KBA232813
How do you test USB Host and USB OTG examples of FX3 SDK?
The USB Host and USB OTG examples of the FX3 SDK (Path: FX3 SDK Installation Path\Cypress\EZ-USB FX3 SDK\1.3\firmware\basic_examples) can be tested using a custom board.
These examples cannot be tested on the SuperSpeed Explorer kit (CYUSB3KIT-003) due to the following reasons:
- The OTG_ID pin of EZ-USB FX3 is left unconnected in the SuperSpeed Explorer kit, which allows FX3 to be used as a USB device only. This pin must be connected to ground if FX3 is used as a dual-role device.
- EZ-USB FX3 does not contain a charge pump; therefore, it cannot source the VBUS supply when used as an OTG-A device or USB Host. When FX3 is used in an OTG-A mode or as USB Host, an external charge pump, either standalone or integrated in a PMIC, must be used to power VBUS. The USB Host and USB OTG examples control VBUS supply using GPIO 21. The SuperSpeed Explorer kit does not have an external power supply/charge pump that can be controlled using a GPIO to drive the VBUS.
- When using the USB port, one of the VBATT/VBUS supplies is required to power the USB I/O. In the examples, when FX3 is used as a USB Host/OTG-A device, the USB block is configured to work off VBATT power instead of VBUS. However, the VBATT pin of FX3 is left unconnected in the SuperSpeed Explorer kit and hence cannot be used.
It is recommended to develop a custom FX3 board similar to FX3 DVK and follow AN77960 to test the USB Host and USB OTG examples on FX3. Refer to the FX3 DVK board schematics and AN70707: EZ-USB FX3/FX3S Hardware Design Guidelines and Schematic Checklist for the custom board design.