Filter
Top Products
CHAPTER 6 USB CONTROLLER
Preliminary User’s Manual S15543EJ1V0UM
351
6.6.5 VR4120A receive processing
This section explains the processing that the V
R
4120A must perform when data is being received.
Figure 6-20. V
R4120A Receive Processing
Sets Pool initialization
Reads USB General Status
Register
(If necessary)
Adds Buffer Directory to Pool
Receive is End ?
Yes
No
Receives the data
from USB.
Reads U_RMRA register
Reads Rx indication
Updates read pointer in mailbox
Read processing of
Rx indication
(1)
(2)
(4)
(5)
(6)
(7)
(3)
Sets Rx Pool
Numbers (1) to (7) do not indicate the order in which the V
R
4120A must perform processing. Instead, these
numbers correspond to those in the following explanation.
(1) First, as part of initialization, the VR
4120A must set Pool configuration.
(2) For receiving, the V
R
4120A must add Buffer Directories to the Pool, if necessary.
(3) The V
R
4120A reads the USB General Status Register.
(4) The VR
4120A checks whether receiving has ended.
(5) If receiving has ended, the V
R
4120A reads USB Rx MailBox Read Address Register (Address:
1000_1088H) to determine the address of MailBox V
R
4120A must read in the next time.
(6) Then, the VR
4120A reads the Rx indication from the indicated MailBox.
(7) The V
R
4120A updates the USB Rx MailBox Read Address Register.