Are there different applications for CE-ATA and ATA on MMC devices?
ATA on MMC is targeted to allow ATA devices, including hard drives to attach to a broad set of existing MMC hosts. Version 1.0 of ATA on MMC Specification makes minimal changes to existing MMC commands to accomplish ATA command transfers in order to be as compatible as possible with existing host implementations. The result is that ATA on MMC Specification ver. 1.0 is suitable for the application of ATA devices in a larger base of existing hosts, but is not necessarily optimized for efficiency.