HD6417660 RENESAS [Renesas Technology Corp], HD6417660 Datasheet - Page 624

• Manufacturer Part Number: HD6417660
• Description: Renesas 32-Bit RISC Microcomputer
• Manufacturer: RENESAS [Renesas Technology Corp]

20.4
20.4.1
The above flowchart shows the operation in the case of in section 20.7, Example of External
Circuitry for USB Function Controller.
In applications that do not require USB cable connection to be detected, processing by the USB
bus connection interrupt is not necessary. Preparations should be made with the bus reset interrupt.
For details, see section 20.7, Example of External Circuitry for USB Function Controller.
Rev. 1.00, 02/04, page 586 of 804
Operation
Cable Connection
No
USB bus connection interrupt
reception complete interrupt
Wait for setup command
UDC core reset release
USB cable connection
D+ pull-up enabled?
Cable disconnected
General output port
Bus reset reception
Bus reset interrupt
VBUS pin = 0 V
UDC core reset
IFR0/VBUS = 1
IFR0/BRST = 1
USB function
Figure 20.4 Cable Connection Operation
Yes
Interrupt request
Interrupt request
start of USB communication
reception complete interrupt
Firmware preparations for
completed, enable D+ pull-up
Wait for setup command
As soon as preparations are
Clear bus reset flag
USB module interrupt
in general output port
Clear VBUS flag
(IFR0/VBUS)
(IFR0/BRST)
Clear FIFOs
Application
setting
Initial
settings