Fujitsu F2MC-16LX Hardware Manual page 297

[bit 6] VON:VBUS connection detection bit
The detection of USB cabling is shown. It is set if VBUS changes from being disconnected ("L" level
kept detecting for not less than 2.6 µs) to 2.6µs continuous application of "H" level potential. The VON
bit is a interrupt factor and writing "1" is ignored. Please clear by writing "0". "1" is read at the read
modification write.
VON
0
1
Note:
The level detection of VBUS is done by 12 MHz sampling. Therefore, VBUS changes for less than
about 83 ns may not be detected. VON is set to "1" if an "H" level is detected for not less than 2.6 µs
in VBUS and VBUS was not disconnected before the detection only when a system reset has been
released.
[bit 5] SUSP: Suspend detection bit
It displays the fact that the USB Function shifts to suspend status. The SUSP bit is an interrupt factor
and writing "1" is ignored. Please clear by writing "0". "1" is read at the read modification write.
SUSP
0
1
[bit 4] SOF:SOF reception detection bit
It indicates that an SOF packet has been received, and the value of the time stamp register is updated.
The SOF bit is an interrupt factor and writing "1" is ignored. Please clear by writing "0". "1" is read at
the read modification write.
SOF
0
1
[bit 3] BRST: Bus reset detection bit
The detection of USB bus reset is displayed. The BRST bit is an interrupt factor and writing "1" is
ignored. Please clear by writing "0". "1" is read at the read modification write.
BRST
0
1
VBUS is a stationary state.
The connection of USB is detected.
Suspend undetection and interruption clear factor
Suspend detection
SOF unreception and interruption clear factor
The SOF packet is received.
USB bus reset undetected and interrupt factors clear
USB bus reset is detected.
CHAPTER 13 USB FUNCTION
Operating mode
Operating mode
Operating mode
Operating mode
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