NEC Network Controller uPD98502 - Manual (Page 345)

CHAPTER 6 USB CONTROLLER
Preliminary User’s Manual S15543EJ1V0UM 345
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
B uffer descriptor
B uffer descriptor
B uffer descriptor
D ata
B uffer
D ata
B uffer
D ata
B uffer
Link pointer
B uffer descriptor
D ata
B uffer
D ata
B uffer
B uffer descriptor
B uffer D irectory
Link pointer
S ize
1-64k B ytes
B uffer descriptor
D ata
B uffer
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.