Introduction | www.seagate.com |
The SATA host adapter and drive share the function of emulating parallel ATA device behavior to provide backward compatibility with existing host systems and software. The Command and Control Block registers, PIO and DMA data transfers, resets, and interrupts are all emulated.
The SATA host adapter contains a set of registers that shadow the contents of the traditional device registers, referred to as the Shadow Register Block. All SATA devices behave like Device 0 devices. For additional information about how SATA emulates parallel ATA, refer to the “Serial ATA International Organization: Serial ATA Revision 3.0”. The specification can be downloaded from
The host adapter may, optionally, emulate a master/slave environment to host software where two devices on
separate SATA ports are represented to host software as a Device 0 (master) and Device 1 (slave) accessed at Note the same set of host bus addresses. A host adapter that emulates a master/slave environment manages two
sets of shadow registers. This is not a typical SATA environment.
10 | NAS HDD Product Manual, Rev. A |
