5.2 Logical Interface
5.2.1 Communication layers
Each of the layers is outlined below.
Physical layer
• Detects, sends, and receives band signals.
• Sends serial data to and receives it from the link layer.
Link layer
• Negotiates against mutual transfer requests between the host system and
device.
• Encodes serial data as 10- or 8-bit data, then converts it into DWORD data.
• 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.
C141-E254 5-15
To Next Page
Loading...
