upd78f0730 Renesas Electronics Corporation., upd78f0730 Datasheet - Page 314

• Manufacturer Part Number: upd78f0730
• Description: 8-bit Single-chip Microcontroller
• Manufacturer: Renesas Electronics Corporation.

314
(29) UF0 GPR register (UF0GPR)
UF0GPR
Bit position
This register controls USBF and the USB interface.
This register is write-only, in 8-bit units. If this register is read, 00H is read. Be sure to clear bits 7 to 2.
FW can reset the USBF by writing 1 to bit 0 of this register. This bit is automatically cleared to 0 after 1 has
been written to it. Writing 0 to this bit is invalid.
1
0
7
0
CONNECT
MRST
Bit name
6
0
CHAPTER 12 USB FUNCTION CONTROLLER (USBF)
This bit sets the output level of the USBPUC pin, which controls connection of the pull-up
resistor connected to D+.
0: USBPUC pin is low level
1: USBPUC pin is high level
For the connection of the USBPUC pin, refer to 12.7.6 USB connection example.
Set this bit to 1 to reset USBF.
Actually, USBF is reset two USB clocks after this bit has been set to 1 by FW and the
write signal has become inactive.
Resetting USBF by the MRST bit while the system clock is operating has the same result
as resetting by the RESET pin (hardware reset) (register value back to default value).
However, the UF0CS and UF0BC registers are not reset by the MRST bit.
5
0
1: Reset
Preliminary User’s Manual U19014EJ1V0UD
4
0
3
0
2
0
CONNECT
Function
1
MRST
0
Address
FF2DH
After reset
00H