Usb Controller Receive Processing; Usb Controller Receive Operations (Normal Mode) - NEC uPD98502 User Manual

6.6.6 USB controller receive processing

This section presents all of the processing performed by USB Controller at data receiving.
6.6.6.1 Normal mode
The following figure illustrates the receive operations performed by USB Controller in Normal Mode.
Figure 6-21. USB Controller Receive Operations (Normal Mode)
(1)
(8)
(9)
S ets R x com pletion bit of co rresponding
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CHAPTER 6 USB CONTROLLER
W aits data
(2)
R e ceives data
from U S B
- C R C verify
- B it S tuffing verify
- N R ZI decode
(3)
S tores the data from U S B to
receive FIFO
(4)
Fetches a new
buffer directory
(5)
E nco unters link poin ter ?
N o
(7)
D M A transfers to
system m em ory
W rites R x indication
U p dates w rite poin ter,
E ndP oint in U _G S R re gister
Preliminary User's Manual S15543EJ1V0UM
(6)
U pdates pool
Inform ation R egisters
Y es