5.2 Logical Interface
5.2.1 Communication layers
Each of the layers is outlined below.
Physical layer
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Detects, sends, and receives band signals.
Sends serial data to and receives it from the link layer.
Link layer
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•
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Negotiates against mutual transfer requests between the host system and device.
Encodes serial data as 10- or
Inserts auxiliary signals (SOF, CRC, and EOF), deletes auxiliary signals, and communicates with the transport and physical layers.
Transport layer
•Exchanges data in communication with the link layer, and builds the frame information structure (FIS).
•Contains a (Shadow) Block Register.
•Reflects the FIS contents to the Block Register.
