Suspend And Resume Operations - Renesas H8S Family Hardware Manual

22.5.3

Suspend and Resume Operations

(1) Suspend Operation
When the USB bus enters the suspend state from the non-suspend state, processing should proceed
as shown below.
USB function
USB cable connected
Bus idle of 3 ms or
more occurs
Suspend/resume
interrupt occurs
(IFR2/SURSF = 1)
Clear SURSF in IFR2 to 0
Check if SURSS in IFR2
USBINT2
USBINT3
Clear SURSE in IER2 to 0
Set SSRSME in IER2 to 1
Figure 22.4 Suspend Operation
Section 22 USB Function Module (USB)
Application
is set to 1
Remote
No
wakeup enabled?
(CTLR/RWUPS = 1?)
Yes
Check remote-wakeup
function enabled
No
System needs to
enter power-down
mode?
Yes
No
Need to enter
software standby
mode?
Yes
Enter software
standby mode
Wait for suspend/
resume interrupt
Rev. 1.00 Mar. 12, 2008 Page 867 of 1178
Check remote-wakeup
function disabled
Set SURSE in IER2 to 1
Clear SSRSME in IER2 to 0
USB module stop
REJ09B0403-0100