SH7280 Datasheet, PDF (1379/1726 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine family

25.5 Operation
25.5.1 Cable Connection
USB function
Cable disconnected
VBUS pin = 0 V
UDC core reset
USB cable connection
Section 25 USB Function Module
Application
USB module interrupt
setting
As soon as preparations are
completed, enable D+ pull-up
in general output port
Initial
settings
No
General output port
D+ pull-up enabled?
Yes
USBIFR1/VBUS = 1
Interrupt request
USB bus connection interrupt
Clear VBUS flag
(USBIFR1/VBUS)
UDC core reset release
Firmware preparations for
start of USB communication
Bus reset reception
USBIFR0/BRST = 1
Bus reset interrupt
Interrupt request
Wait for setup command
reception complete interrupt
Clear bus reset flag
(USBIFR0/BRST)
Clear FIFOs
(EP0, EP1, EP2, EP3)
Wait for setup command
reception complete interrupt
Figure 25.2 Cable Connection Operation
Rev. 1.00 Jun. 26, 2008 Page 1349 of 1692
REJ09B0393-0100