Datasheet

Section 14 Universal Serial Bus (USB)
Rev.7.00 Dec. 24, 2008 Page 532 of 698
REJ09B0074-0700
(1)
(2)
(3)
(3)
(3)
(3)
(4)
(4)
(4)
(5)
(6)
(7)
(7)
(7)
Power-down
mode
4 ms
wait for
oscillator
to stabilize
2 ms wait
for USB
operation
clock
to stabilize
USB module stop state
USB operation
resumes
(8)
(9)
(9)
(10)
(10)
(11)
(11)
(12)
(13)
(14)
(15)
(16)
(17)
(18)
(18)
(21)
(22)
(23)
USB bus state
IRQ6
ISR/IRQ6F
UIFR3/SPRSi
USPND
UIFR3/SPRSs
UIFR3/SOF
USB module
stop
power-down mode
System clock
Normal Suspend SOF
φ
USB internal
clock
UIFR3/
CK48READY
CLK48
(48MHz)
USB operating
clock (48MHz)
(14)
(19)
(19)
(20)
(24)
Resume → Normal
Figure 14.29 Timing Chart
14.8.13 USB External Circuit Example
The USB external circuit examples are used for reference only. In actual board design, carefully
check the system operation.
In addition, the USB external circuit examples cannot guarantee the correct system operation. The
user must individually take measures against external surges or ESD noise by incorporating
protective diodes or other components if necessary.