Are you going to connect the a USB Storage Device (Ex. pen drive) to FX3's USB interface? If so, do you want FX3 to act in host mode?
If so, you can refer the UsbHost example in FX3 SDk for host mode operation where it talks to a mass storage device. But GPIF functionality is not available in that example.
We recommend you to go through the slave fifo example codes for getting data from the GPIF (refer An65974 application note) or GpifToUsb example. (In the GpifToUSb Example, if you enable the STREAMING_MANUAL macro. Now the project will have a Dma Manual Channel. Whenever you receive a data buffer from the GPIF, the GpifToUsbDmaCallback will be triggered inside which you can access the data and store it in the RAM if required. (You can use the CyU3PDmaSetupRecvBuffer API if required to receive the data from the dma channel and divert it to your own memory in the RAM. This API is being used in some of our other example projects.)
So, as a combination of UsbHost project and GpiftoUsb project, you can implement this.
- Madhu Sudhan