Datasheet

Section 16 USB Function Module (USB)
R01UH0309EJ0500 Rev. 5.00 Page 993 of 1408
Sep 24, 2012
H8S/2456, H8S/2456R, H8S/2454 Group
(2) Resume Operation from Up-Stream
If the USB bus enters the non-suspend state from the suspend state by resume signal output from
up-stream, perform the operation as shown in figure 16.6.
USB function
USB cable connected
USB bus in suspend state
Cancel 48-MHz USB clock
module stop.
(EXMSTPCRL/MSTP17 = 0)
Resume interrupt is
requested from the
up-stream.
Suspend/resume
interrupt occurs.
(IFR0/SURSF = 1)
RESUME
USBINTN2 or
USBINTN3
Clear SURSF in IFR0 to 0.
Check if SURSS in IFR0 is 0.
Return to normal state.
48-MHz USB clock
oscillation started
Application
Set SURSFE in IER0 to 1.
Clear SSRSME IN IER0 to 0.
Cancel software standby mode.
Wait for system clock oscillation
to be settled.
Wait for 48-MHz USB clock
oscillation to be settled.
Figure 16.6 Resume Operation from Up-Stream