Ещё о недостаках в "Limitations" из евонного хелпа написано:
The current version of the CodeVisionAVR C compiler has the following limitations:
· the long long, double, _Complex and _Imaginary data types are not yet supported
· the bit data type is not supported for the reduced core, used in chips like ATtiny10
· functions with variable number of parameters are not supported for reduced core chips
· signal handling (signal.h) is not implemented yet
· date and time functions (time.h) are not implemented yet
· extended multibyte/wide character utilities (wchar.h) are not implemented
· wide character classification and mapping utilities (wctype.h) are not implemented
· the printf, sprintf, snprintf, vprintf, vsprintf and vsnprintf Standard C Input/Output Functions can’t output strings longer than 255 characters for the %s format specifier
· the I2C, Philips PCF8563, Philips PCF8583, Maxim/Dallas Semiconductor DS1302, DS1307, DS1621, DS2430, DS2433, National Semiconductor LM75 libraries do not yet support the ATxmega chips
· the size of the compiled code is limited for the Evaluation version
· the libraries for Philips PCF8563, Philips PCF8583, Maxim/Dallas Semiconductor DS1302, DS1307, 4x40 character LCD, ATxmega TWI functions and EBI support are not available in the Evaluation version.