To talk to SPI from the host side, it is better to use vendor commands through the control endpoint. You can use the control center tool to send the vendor commands. The source code of the control center is given in the SDK. You can refer the source code to send vendor command using your own host application.
The example firmware in the SDK Location "C:\Program Files (x86)\Cypress\EZ-USB FX3 SDK\1.3\firmware\serialif_examples\cyfxusbspidmamode" and "C:\Program Files (x86)\Cypress\EZ-USB FX3 SDK\1.3\firmware\serialif_examples\cyfxusbspiregmode" use vendor commands from the host to do SPI Transfers.
You can refer these examples for implementation of FX3 firmware.
Also, CyU3PDebugPrint is not the correcr way of sending anf receive data from Hyperterminal. You need to have a COM Port interface in your project in addition to the existing interfaces. FX3 has been configured as a COM Port in the example project "C:\Program Files (x86)\Cypress\EZ-USB FX3 SDK\1.3\firmware\serialif_examples\cyfxusbuart"
Refer this example to add this functionality in your project also. If you have any trouble in intergration, please create a Tech Support Case
- Madhu Sudhan