Using Busy Bee Microcontroller


I have a few EFM8 Busy Bee 1's(in SMD package) lying around and I wanted to know how to program them.
Here is the datasheet-

These things are very tiny and might come in handy in tight spaces.


The EFM8 series chips are 8051-like microcontrollers that are not compatible with Arduino.
It might be an interesting experiment to make them compatible. While there is no gcc that generates 8051 code, and the only open-source C compiler doesn't do C++, I think Si-labs has some sort of deal where you can use Keil's (normally not-even-close-to-free) compiler tools for their chips...