> In the SD spec v6.x the SD function extension registers for performance > enhancements were introduced. As a part of this an optional internal cache > on > the SD card can be used to improve performance. Just to verify that you are aware of that: In addition to the extension Registers that were defined in the physical core spec, there was a separate document that was released that suggest a common OS API's to those registers. It is called "SD specification part A5, SD Extensions API specification". Thanks, Avri
