CHAPTER 12 USB FUNCTION CONTROLLER (USBF)
Preliminary User’s Manual U19014EJ1V0UD
348
12.4.4 Peripheral control register
(1) USB function 0 buffer control register (UF0BC)
This register performs enable control and floating control on the input buffer of the USB function.
This register can be read or written in 8-bit units.
0
UF0BC
0
5
0
0
3
0
2
0
1
UBFIEN
UBFIOR
Address
FF8BH
After reset
00H
0
4
6
7
Bit position
Bit name
Function
1
UBFIEN
This bit controls use of the USB buffer.
1: Buffer valid
0: Buffer invalid
Caution Clear this bit to 0 when the USB is not used. If this bit is set to 1, a
current of 3 mA (TYP.) constantly flows, regardless of whether the USB is
used or not.
0
UBFIOR
This bit controls use of floating measures of the USB buffer.
1: Disables floating measures
0: Enables floating measures
This bit prevents erroneous recognition of Bus Reset, Suspend, and Resume due to an
undefined value when a cable is not connected (when data input is floated). When this
bit is set to 1, control the processing for floating by the VBUS signal (which recognizes
cable connection).
electronic components distributor