I understand that you will need your host application to change the USB-Serial configuration.
Dynamically changing the configuration, for example, just changing SCB0 configuration from SPI to I2C is not possible.
One possible way is to save the required configuration as .cyusb using the configuration utility and download the same to the device through a command line utility. You can refer to this thread for the command line utility to download the configuration to the USB-Serial Device.
Okay. I understand what you said.
Thanks for your reply.