HD6417727BP160CV Datasheet, PDF (762/1098 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH™ RISC engine Family/ SH7700 Series

Section 23 USB Function Controller
23.6 Operation
23.6.1 Cable Connection
USB function
Cable disconnection
VBUS pin = 0 V
UDC core reset in progress
Application
Connect USB cable
USBF_VBUS pin = 1
(USBIFR1/VBUSMN = 1)
USBIFR1/VBUSF = 1
Interrupt request
USB bus connection interrupt
Clear VBUS flag
(USBIFR1/VBUSF)
Clear UDC core reset
Prepare firmware since
USB communication starts
Bus reset
USBIFR0/BRST = 1
Bus reset interrupt
Interrupt request
Clear bus reset flag
(USBIFR0/BRST)
Wait receive-end interrupt
of set-up command
Clear FIFOs
(EP0, EP1, EP2, EP3)
Wait receive-end interrupt
of set-up command
Figure 23.2 Cable Connection Operation
The above flowchart shows the operation in cable connection. When a USB connection interrupt
occurs, connection can be detected by confirming the status of the USBF_VBUS pin.
Processing by a USB bus connection interrupt is unnecessary for applications in which USB cable
connection is not required to be detected. Prepare processing by a bus reset interrupt.
Rev.6.00 Mar. 27, 2009 Page 704 of 1036
REJ09B0254-0600