A microcontroller device has a housing with a plurality of external pins having a plurality of input/output pins, a first microcontroller with a first central processing unit (CPU), a first system bus coupled with the first CPU, first memory coupled with the first system bus, and a first plurality of peripheral devices coupled with the first system bus, a second microcontroller with a second central processing unit (CPU), a second system bus coupled with the second CPU, second memory coupled with the second system bus, and a second plurality of peripheral devices coupled with the second system bus, and a pad ownership multiplexer unit being controllable to assign control of the input/output pins to either the first microcontroller or the second microcontroller, wherein the number of external pins is less than the sum of a data buswidth of the first and second microcontroller.