Attached are headers for the OTP parts C8051T60x, C8051T61x, C8051T63x series and the Flash part C8051F336. Thes headers are currently missing from the include/mcs51 directory.
These headers use the compiler.h macros which I assume is the preferred method for mcs51 headers. If not then I can provide versions that don't use these macros.
I'm fairly confident that these are accurate, but they have not been rigourously tested. I used the SiLab data sheets and AN280, AN330 and AN339 as references.