SV: cdata attribute value normalization in schema?

>W3C XML Schema's whitespace normalization is independent of XML's and
>happens logically after it.

okay, well this leads me back to my problem then. The xml normalization for
attributes is dependent on if "the attribute type is not CDATA", if it isn't
leading/trailing whitespace is discarded, if it is they aren't. How do I via
xml schema specify that an attribute is CDATA? Is an CDATA attribute type
just a string? or anything else?