CHAPTER 6 USB CONTROLLER
354 Preliminary User’s Manual S15543EJ1V0UM
6.6.6.2 Assemble modeThe following figure illustrates the receive operations performed by USB Controller in Assemble Mode.Figure 6-22. USB Controller Receive Operations (Assemble Mode)
Stores the data from USB to
receive FIFO
Receives data
from USB
- CRC verify
- Bit Stuffing ve rify
- NRZI decode
Buffer is remainin g
in system memory
area ?
Yes
No
DMA trans fers to
system memory
Writes Rx indication
Updates write pointer,
Sets Rx completion bit of corresponding
EndPoint in UGSR register
(1)
(2)
(4)
(8)
(10)
(11)
(3)
Waits data
Fetches new
buffer descriptor
Encounters link pointer ?
Updates Pool Information
Registers
No
Yes
Last data ?
(9)
Yes
No
(5)
(6)
(7)