Usb-Io Switch; I²C Pull-Up Resistors - Panasonic PAN9520 ETU User Manual

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PAN9520 ETU Evaluation Tool

3.11 USB-IO Switch

GPIO 19 and GPIO 20 can be configured to work as USB interface and are thus connected to
the module native USB connector "USB Module". The connection between the module and the
USB connector is permanent. To avoid bad signal integrity, caused by stubs or other
disturbances, all other peripherals can be disconnected from the USB signal lines. Therefore,
the switch "USB-IO SW" is used. The "USB-IO SW" connects either a set of USB-related
pull-resistors or the additional periphery (breakout pin header and FT232 RTS and CTS signals)
to the USB lines.
Connection Description
Peripherals are connected to the USB traces and
thus GPIO 19 and GPIO 20.
Connected peripherals are the breakout pin header
and CTS/RTS lines of the FT232 USB to UART1 IC
(can be still disconnected by "UART1" pin header).
All peripherals are disconnected from the USB
traces.
Instead, a 1.5 kΩ pull-up resistor is connected to
USB D+ (GPIO 20), which is the configuration for a
full-speed USB device.
3.12 I²C Pull-Up Resistors
GPIOs 7 and GPIO 8 are used for I²C pins on the Arduino socket and SCCB (Serial Camera
Control Bus) pins on the camera connector. Therefore, 4.7 kΩ pull-up resistors are connected to
these GPIOs per default. They can be disconnected by unplugging the jumpers on the pin
header "I C Pull".
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User Guide Rev. 1.0
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