
SATA Technical Overview 41
Layer 3 (Transport Layer) provides formats for conveying ATA commands for processing by the
link layer.
Layer 4 (Application Layer) provides the commands to communicate between a host and device.
Although both host and device implement peer architectural layers, operations within them can
differ between host and device. The detailed protocol that must be implemented at each layer is defined
in a series of state diagrams. There is a set of state diagrams for each architectural layer.
Serial physical
interface plant
Serial digital link
control
Serial physical
interface plant
Serial digital link
control
Serial digital ...