Renesas SH7641 - Manual (Page 840)

Section 20 USB Function Module
Rev. 4.00 Sep. 14, 2005 Page 790 of 982
REJ09B0023-0400
This LSI
IRQ1
IRQ1_SUSPEND
USBCTRL/
SUSPEND
USBIFR2/
SUSPS
USBIFR2/
AWAKE
IRQ0_AWAKE
IRQ0
0
S
Q
1
0
1
USB suspend
signal (internal signal)
AWAKE signal
(internal signal)
IRQ1 interrupt
IRQ0 interrupt
Interrupt controller
(INTC)
S
Q
Figure 20.19
IRQ0 and IRQ1 Interrupt Circuitry
USBIFR2/SUSPS
cleared
USBIFR2/AWAKE
cleared
IRQ0 interrupt
detected
RTE instruction RTE instruction
Peripheral
clock
IRQ1_USB
SUSPEND
IRQ0_
AWAKE
Normal
operation
IRQ1 interrupt
routine
Standby
state
IRQ0 interrupt
routine
IRQ1 interrupt
routine
Normal
operation
IRQ1 interrupt
detected
SLEEP
instruction issued
Figure 20.20 USB Standby Operation Timing
20.9.2 Usage Example of USB Bus Power Control Method
Figures 20.21 to 20.23 show flowcharts for initializing, entering standby mode and awaking when
using the USB bus power control method.