Datasheet

Section 22 USB Function Module (USB)
Rev. 2.00 Aug. 20, 2008 Page 866 of 1198
REJ09B0403-0200
(2) Resume Operation from Up-Stream
When the USB bus enters the non-suspend state from the suspend state by resume signal output
from up-stream, processing should proceed as shown below.
USB cable connected
USB bus in suspend state
Resume interrupts is
requested from the
up-stream.
Suspend/resume
interrupt occurs.
(IFR2/SURSF = 1)
RESUME
Cancel software
standby mode
Clear SURSF in IFR2 to 0
Set SURSE in IER2 to 1
Clear SSRSME in IER2 to 0
Check if SURSS in IFR2 is
cleared to 0
Software standby
mode ?
USB module
stopped?
Oscillation stabilization
time has passed?
No
No
No
Ye s
Ye s
Ye s
Start USB operating
clock oscillation
Cancel USB module stop
Return to normal state
USB function
Application
Figure 22.5 Resume Operation from Up-Stream