I am evaluating the FX2LP for use in our future products. I have the EZ-USB CY3684/3674 Advanced Development board and I'm reading all the associated docs that came with it. Now that I'm ready to start looking at host code to talk to the USB device, I have been looking at CyAPI lib. The documentation for CyAPI says that it is a "high-level programming interface to the CyUsb.sys device driver. The library is only able to communicate with USB devices that are served by this driver." 

Elsewhere in the documentation, it says to redistribute Cypress drivers, it's recommended that it be renamed (let's say MyUSBDev.sys)..  so with it renamed, how can CyAPI still talk to it? I assume that embedded in CyAPI.lib binary is an explicit reference to "CyUsb.sys" in a CreateFile call or something..  So CyAPI.lib would only be useful in host apps that deal with the un-renamed CyUsb.sys?

Nope. CyAPI uses DriverGUID to get handle and talk to CyUSB.sys. so even if CyUSB.sys is renamed CyAPI would still be able to talk to it.

Cheers,

Anand

Ok, thank you! Next question: the DID is 8613 for the FX2LP.. and for the examples it is 1004. I can't find anything, anywhere, in the firmware nor on the host side that defines that. The examples often just refer to some variable's address (bulkloop/fw.c) that got filled in seemingly out of nowhere?  Where/What causes the device to become DID 1004 when I download bulkloop.hex ?

Thank you for your help! 

doh.. nevermind. found it in the dscr.a51 files. My searches didn't find it because it's stored in little endian assembly.. 0410