The Advanced Host Controller Interface (AHCI) specification describes the register-level interface for a host controller for Serial ATA. The specification includes a description of the interface between system software and the host controller hardware. This specification is intended for hardware component designers, system builders, and device driver (software) developers.
Implementation of the Advanced Host Controller Interface specification requires a license from Intel. Contributors of the Advanced Host Controller Interface specification for Serial ATA have signed the Advanced Host Controller Interface specification for Serial ATA - contributors agreement in order to be licensed to use and implement this specification. This contributors agreement provides Contributors with a reciprocal, royalty-free license to certain intellectual property rights from Intel and other Contributors for their products that are compliant with the licensed versions of the Advanced Host Controller Interface specification for Serial ATA.
Intel intends to continue including suitable inputs, comments, and suggestions from contributors to refine and update the Advanced Host Controller Interface specification through a series of specification releases that will be marked as being revision 1.x of the specification. Licensing of the applicable final specification of the AHCI Specification (as defined in the contributors agreement) allows the implementation of both discrete and integrated compliant AHCI host controllers. Licensing of the applicable draft version of the applicable specification level (also defined in the contributors agreement) will allow the implementation of compliant, discrete AHCI host controllers only.
The latest revision of the specification is revision 1.3. Subsequent revision 1.x levels of the specification will be completed by Intel at its discretion as time and circumstances permit.