Jan Thogersen

HCS12. Address space of external devices in expanded wide mode?

Discussion created by Jan Thogersen on Mar 15, 2006
Latest reply on Mar 15, 2006 by Steve Mcaslan

After reading the app note on accessing external devices, another thing that troubles me is the address space when using expanded wide mode. For me it looks like that when using the expanded wide mode all addresses from 0x4000 to 0xFFFF is taken from outside? Including the vector area? Is this really true?

I only need to attach a 16bit wide DAC to my design… so I only need a very small address space for that. 4 – 16bit addresses actually. Is it possible for me to place that on the bus and still be able to use all the internal flash including the vector space?

Would it be better and just as fast if I just emulated an addr/data bus on some ports instead?

Thanks in advance!

Best regards
Jan Thogersen

Message Edited by Trace on 03-14-200606:08 PM