Hello.
I need to make a hardware that allows a Raspberry to modify the firmware programmed in a MC9S08AC16.
I cannot incorporate a commercial development board.
Is there a dedicated integrated circuit or published program to incorporate it into another microcontroller that is the link between Raspberry and MC9S08AC16, that receives data through SPI or SCI and comes out with the BDC protocol?
Do you want a serial bootloader?
If this is the case, please check the an2295
https://www.nxp.com/docs/en/application-note/AN2295.pdf
I hope this will help you
Regards
Vicente G