NEC Network Controller uPD98502 - Manual (Page 335)

CHAPTER 6 USB CONTROLLER
Preliminary User’s Manual S15543EJ1V0UM 335
Figure 6-5. Tx Buffer Configuration
Buffer descriptor
Buffer descriptor
Buffer descriptor
Data
Buffer
Data
Buffer
Buffer desc.(L=1)
Data
Buffer
Data
Buffer
Link pointer
Buffer descriptor
Data
Buffer
Tx Packet
Buffer
Directory
A transmit packet is configured by breaking up multiple data buffers in system memory. These data buffers are
bundled together in the buffer directory.
The formats of the Buffer directory, Buffer descriptor, and Link Pointer in the Tx buffer are as shown below.