The USB-Serial config utility is only for use in USB-Serial devices and not for CX3.
For CX3, you need to program it like how you'd program an FX3 device. Use Control Center, select your device and then Program > FX3 > RAM.
Thanks, I didn't know it works that way.
Where do I get Control Center? I downloaded FX3 SDK, but it only has EZ USB Suite.
If you've downloaded the SDK, then you can find Control Center at:
Start Menu > All Programs > Cypress > Cypress USBSuite
We have 4 example projects for CX3 which you can find at:
C:\Program Files (x86)\Cypress\EZ-USB FX3 SDK\1.3\firmware\cx3_examples
(the folder location changes depending on where you installed the SDK and your OS version -- 32 vs 64-bit)
And to develop your firmware, use the EZ-USB Suite (a modified version of Eclipse) which is available at:
Start Menu > All Programs > Cypress > Eclipse > EZ-USB Suite