
SATA Transport Layer 213
DMA Auto-Activate Bit Summary
SATA II provides extension to “DMA setup” FIS.
This eliminates the requirement to use the “DMA activate” FIS.
– SATA originally required the use of the DMA Setup FIS, followed by the DMA Activate FIS.
The “Auto-Activate” field is introduced into the DMA Setup FIS.
– This field was “reserved” in prior versions of the SATA Specifications.
This results in overhead reduction for DMA transfers due to one less FIS transaction required
during data transfers.
SATA-2 DMA Setup FIS Changes for Auto-Activate
byte n+3 byte n+2 byte n+1 byte n
SOF D23.1 D23.1 D21.5 K28.3
Data dword 0 Reserved Reserved ...