Hi:
I suggest looking into the Hybrid DSP-MCU processors from Freescale: MC56F83xx
The following link is to a UPS Reference Design
http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=RD56F8300OUPS&parentCode=56F8147&node...Check also the Application Note AN3113
It has a full description of the UPS circuit and software implementation.
IMHO, you might have a hard time trying to implement an complete Online UPS with a HC08 processor.
Regards,
Alex
Message Edited by alex_spotw on 2006-07-28 12:28 PM