Datasheet

Table Of Contents
Section 15 Universal Serial Bus Interface (USB)
REJ09B0140-0900 Rev. 9.00 Page 555 of 846
Sep 16, 2010
H8S/2215 Group
(4) Remote-Wakeup Interrupt Processing
Figure 15.11 is a flowchart of remote-wakeup interrupt processing.
USB function
Firmware
Remote-wakeup
interrupt processing
USB operating clock stabilization
detection interrupt processing
Start USB operating
clock oscillation
Output resume signal
to USB bus
A suspend/resume
interrupt occurs
A USB operating clock
stabilization detection
interrupt occurs
Wait for resume signal
from up-stream
Clear USB operating clock
stabilization detection flag
(Clear CK48READY
in UIFR3 to 0)
Execute remote-wakeup
(Set DVR in UDRR to 1)
Resume interrupt
processing
(see figure 15.9)
Clear USB module
stop mode
(Clear SPRSi in UIFR3
to 0)
Wait for USB operating
clock stabilization
Resume main process
USB operating
clock stabilization time
has passed?
Yes
Yes
No
EXIRQx
IRQ6
No
Is remote-
wakeup enabled
by host?
NMI or IRQx
Remote-
wakeup
Figure 15.11 Example Flowchart of Remote-Wakeup Interrupt Processing