Datasheet

Table Of Contents
Section 15 Universal Serial Bus Interface (USB)
Page 550 of 846 REJ09B0140-0900 Rev. 9.00
Sep 16, 2010
H8S/2215 Group
(3) USB Cable Disconnection (When USB Module Stop or Software Standby Is Not Used)
If the USB cable enters the disconnection state from the connection state in an application (self
powered) where USB module stop or software standby mode is not used, perform the operation
shown in figure 15.6. In bus-powered mode, the power is automatically turned off when the USB
cable is disconnected and the following processing is not required.
Disconnect the USB cable
A VBUS interrupt occurs
USB function
Firmware
Reset the UDC core
Clear VBUSi in UIFR3 to 0
Check if VBUSs in UIFR3
is cleared to 0
Enable D + pull-up by
the port
Wait for a USB cable
connection
Reset the UDC core
Write UDCRST in UCTLR to1
*
*
Stop SOF marker function
EXIRQx
Note:
A VBUS interrupt in the USB module cannot be detected in the software standby state
or in the USB module stop state.
No
Ye s
SOF marker
function enabled?
Stop the SOF marker function
Clear SFME in UCTLR to 0
Figure 15.6 USB Cable Disconnection
(When USB Module Stop or Software Standby Is Not Used)