8bit MCU+Radio transceiver on a single chip

Hi,

I am looking for an 8 bit MCU+868MHZ radio on a single chip.
I narrowed on ATA8510, it has an AVR core so migrating from Atmega328 would not be that difficult. However its a closed chip, in the sense that its programming details related documentation is not available publicly.

What are the other chips that I could look at?

Thanks and Regards,
WI

Texas Instruments makes a bunch, and open source C compilers are available. Look up CC1110 and SDCC.