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Remote-Wakeup Operation
When the USB bus enters the non-suspend (resume) state from the suspend state by the remote-
wakeup signal output from this function, processing should proceed as shown below.
USB function
USB cable connected
USB bus in suspend state
Start USB operating
clock oscillation
Resume output signal
Suspend/resume
interrupt occurs.
(IFR2/SURSF = 1)
Cancel software
standby mode
Oscillation
stabilization time
has passed?
RESUME
Figure 22.8 Remote-Wakeup
Section 22 USB Function Module (USB)
Application
Remote
wakeup enabled?
(CTLR/RWUPS = 1?)
Yes
Bus wakeup source
generated
Yes
Software standby
mode ?
No
No
Yes
USB module
stopped?
Yes
Cancel USB module stop
Remote wakeup execution
(CTLR/RSME= 1)
Clear SURSF in IFR2 to 0
Check if SURSS in IFR2 is
cleared to 0
Return to normal state
Rev. 1.00 Mar. 12, 2008 Page 871 of 1178
No
Wait for resume
from up-stream
No
REJ09B0403-0100
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