CHAPTER 12 USB FUNCTION CONTROLLER (USBF)
Preliminary User’s Manual U19014EJ1V0UD
391
12.7.6 USB connection example
Figure 12-26. USB Connection Example
PD78F0730
µ
IC
UV
DD
USBPUC
USBP
USBM
D+
D-
27
Ω
±
5 %
27
Ω
±
5 %
1.5 k
Ω
±
5 %
CONNECT
UF0GPR
(1) Pull-up control of D+
To prohibit connection notification (D+ pull-up) to the USB host/HUB (such as while higher priority processing
or initialization processing is under execution), the system must control pull-up of D+ via the USBPUC pin.
In the circuit example in Figure 12-26, D+ is pulled up because the USBPUC pin is set to output low level by
the initial value after reset.
To prohibit pull-up of D+, be sure to set the CONNECT bit of the UF0GPR register to 1 after reset, and then
output the high level from the USBPUC pin.
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