We do not have a specific PID range. You can use the Cypress VID for development purposes along with your own random PID. But the product should never be released with Cypress VID. The normal way of functioning is that, once you have acquired your own VID from USB-IF you can assign the Product IDs (PIDs) as you see fit. You can check in the cyusb.inf file that you are using and assign unused PIDs to your new devices so that they are not conflicting with the older devices that have already been assigned VID/PID.