Datasheet

Section 22 USB Function Module (USB)
Rev. 2.00 Aug. 20, 2008 Page 870 of 1198
REJ09B0403-0200
22.5.4 Control Transfer
Control transfer consists of three stages: setup, data (not always included), and status (figure 22.9).
The data stage comprises a number of bus transactions. Operation flowcharts for each stage are
shown below.
Control-in
Setup stage Data stage Status stage
Control-out
No data
SETUP(0)
DATA0
SETUP(0)
DATA0
SETUP(0)
DATA0
IN(1)
DATA1
OUT(1)
DATA1
IN(0)
DATA0
OUT(0)
. . .
. . .
DATA0
IN(0/1)
DATA0/1
OUT(0/1)
DATA0/1
OUT(1)
DATA1
IN(1)
DATA1
IN(1)
DATA1
Figure 22.9 Transfer Stages in Control Transfer