CHAPTER 6 USB CONTROLLER
Preliminary User’s Manual S15543EJ1V0UM
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6.6.2 Rx Buffer configuration
Data received from the USB is stored into a receive pool in system memory.
USB Controller uses three receive pools. The configuration of the receive pools is shown below.
Figure 6-13. Receive Buffer Configuration
Buffer descriptor
Buffer descriptor
Buffer descriptor
Data
Buffer
Data
Buffer
Data
Buffer
Link pointer
Buffer descriptor
Data
Buffer
Data
Buffer
Buffer descriptor
Buffer Directory
Link pointer
Size
1-64k Bytes
Buffer descriptor
Data
Buffer
The receive buffer is composed of the Buffer Directory and Data Buffer. The receive buffer is prepared in system
memory by the V
R
4120A.
The formats of the Buffer Directory, Buffer descriptor, and Link Pointer are each described below.