Fujitsu MHY2040BH, Product/Maintenance Manual, Page: 90 / 322

Interface
5-12 C141-E262
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.