NEC Network Controller uPD98502 - Manual (Page 354)

CHAPTER 6 USB CONTROLLER
354 Preliminary User’s Manual S15543EJ1V0UM
6.6.6.2 Assemble mode
The following figure illustrates the receive operations performed by USB Controller in Assemble Mode.
Figure 6-22. USB Controller Receive Operations (Assemble Mode)
S tores the data from U S B to
receive F IF O
R eceives data
from U SB
- C R C ve rify
- Bit S tuffing verify
- N R Z I d ecode
B uffer is remaining
in system memory
area ?
Y es
N o
D M A transfers to
system memory
W rites R x indication
U pdates write po inter,
S ets R x completion bit of corresp onding
E ndPoin t in U G S R register
(1)
(2)
(4)
(8)
(10)
(11)
(3)
W aits data
F etches new
buffer descriptor
E ncounters link p ointer ?
U pdates P ool Information
R egisters
N o
Y es
Last data ?
(9)
Y es
N o
(5)
(6)
(7)