User's Manual

LE920A4 HW User Guide Hardware Interfaces
Doc#: 1VV0301261 General Purpose I/O
Rev. 4.3 Page 91 of 123 2017-12-07
PAD Signal I/O Initial Function Alternate Function Type
Drive
Strength
AK3 GPIO_18 I/O WIFI_SDIO_D3 Configurable GPIO CMOS 1.8V 2-16 mA
AM3 GPIO_19 I/O WIFI_SDIO_CLK Configurable GPIO CMOS 1.8V 2-16 mA
AJ18 GPIO_31 I/O UART_RI Configurable GPIO CMOS 1.8V 2-16 mA
AG18 GPIO_32 I/O UART_DSR Configurable GPIO CMOS 1.8V 2-16 mA
AE18 GPIO_33 I/O UART_DCD Configurable GPIO CMOS 1.8V 2-16 mA
AC18 GPIO_34 I/O UART_DTR Configurable GPIO CMOS 1.8V 2-16 mA
P19 GPIO_35 I/O SPI_CLK Configurable GPIO CMOS 1.8V 2-16 mA
M19 GPIO_36 I/O SPI_MISO Configurable GPIO CMOS 1.8V 2-16 mA
K19 GPIO_37 I/O SPI_MOSI Configurable GPIO CMOS 1.8V 2-16 mA
N18 GPIO_38 I/O SPI_CS Configurable GPIO CMOS 1.8V 2-16 mA
NOTE:
To avoid a back-powering effect, it is recommended to avoid having any
HIGH logic level signal applied to the digital pins of the module when it is
powered OFF or during an ON/OFF transition.
NOTE:
The GPIOs can also be used as alternate I2C function. Refer to Section
8.5.2, I2C - Inter-integrated Circuit.
8.7.1. Using a GPIO Pad as Input
GPIO pads, when used as inputs, can be connected to a digital output of another device
and report its status, provided this device has interface levels compatible with the 1.8V
CMOS levels of the GPIO.
If the digital output of the device is connected with the GPIO input, the pad has interface
levels different from the 1.8V CMOS. It can be buffered with an open collector transistor
with a 47 kΩ pull-up resistor to 1.8V.