The PSoC hardware isn't fully documented, either. Some critical parts of the UDB architecture (which is arguably the most interesting part of the product!) aren't explained in the register documentation -- for example, the registers which control routing are described as "RAM configuration bytes for channel", with no further explanation.

If you're using Cypress's IDE, it can generate the required configuration data for you. But if you want to take off on your own, you're out of luck.