Fujitsu MHT2060BH Manual Do Utilizador

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5.2   Logical Interface 
C141-E203-01EN 5-9 
5.2   Logical Interface 
The host system and the device communicate with each other by sending and 
receiving serial data. 
The host and the device have several dedicated communication layers between 
them.  These layers have different functions, enabling communication between the 
different levels of layers within the host or device and between layers at the same 
level that link the host and device. 
Figure 5.2 is a conceptual diagram of the communication layers. 
 
Host: 
Software control 
Buffer Memory 
DMA engine(s) 
Host located layers 
Physical Layer  
Link Layer 
 
Transport Layer 
Device located layers 
 Physical Layer 
Link Layer 
Transport Layer 
Device: 
Software control 
Buffer memory 
DMA engine(s) 
Application 
layer 4 
Transport 
layer 3 
Link 
layer 2 
Physical 
layer 1 
Shadow Block Register 
Block Register 
 
Figure 5.2  Conceptual diagram of communication layers