Control Transfer Support Function - Epson S2R72V18 Technical Manual

1. Functions
1.4.4.3

Control Transfer Support Function

This LSI includes a function for automatic stage management of a series of control transfers. Using
this function eliminates the need for the firmware to manage each stage as an individual transaction.
The control transfer support function is enabled for channel CH0. The control transfer using this
function is shown below. The firmware performs the processing in steps (1) to (4) and (7).
(1) Set the following basic setting registers appropriately for channel CH0.
Transfer speed (H_CH0Config_0.SpeedMode), maximum packet size (H_CH0MaxPktSize),
USB address (H_CH0FuncAdrs.FuncAdrs), endpoint number (H_CH0FuncAdrs.EP_Number),
FIFO area (AREAn{n=0-5}StartAdrs_H,L, AREAn{n=0-5}EndAdrs_H,L), FIFO area join
(AREAn{n=0-5}Join_1.JoinEP0CH0)
(2) Write the setup data (8 bytes) to the setup registers (H_CH0SETUP_0 to 7).
(3) If the data stage is in the OUT direction, write the data to be sent to the FIFO area joined to
CH0. If the data stage is in the IN direction, clear the FIFO area joined to CH0.
(4) Set the control transfer support execute (H_CTL_SupportControl.CTL_SupportGo). The
control transfer stage (H_CTL_SupportControl.CTL_SupportState) value is written to the
H_CTL_SupportControl register here as "Idle(00b)."
(5) Execute the SETUP transaction using the SETUP register data (8 bytes) (SETUP stage).
74
Set
Completion confirmation
Fig. 1-36 Control transfer support function control
Host
F/W
Ctl
SETUP
Ctl
DATA
Ctl
STATUS
EPSON
S2R72V18 Technical Manual (Rev.1.00)
Host Controller
(Channel Resister)
H/W
Channel-0
(Ctl only)