User's Manual

18 Single Board Computer
2. GPIO header
This 40-pin GPIO (General-purpose Input/Output) header can be
designated (in software) as an input or output pin and is used for
a wide range of purposes. Of the 40 pins, 28 are GPIO pins (shared
with SPI/UART/I2C pins). Please refer to the table below for the pin
denitions for Linux Yocto.
Linux Yocto
Pin denition Pin# 40P GPIO Pin# Pin denition
3V 1 2
5V
I2C2_SDA (default)
ENET1_1588_EVENT1_OUT
GPIO5_IO17
145 3 4
I2C2_SCL (default)
ENET1_1588_EVENT1_IN
GPIO5_IO16
144 5 6 GND
UART3_TX
UART1_RTS_B (default)
GPIO5_IO27
155 7 8 151
UART1_TX (default)
ECSPI3_MOSI
GPIO5_IO23
GND 9 10 150
UART1_RX (default)
ECSPI3_SCLK
GPIO5_IO22
UART3_RX
UART1_CTS_B (default)
GPIO5_IO26
154 11 12 121
SAI2_TX_BCLK (default)
SAI5_TX_DATA2
GPIO4_IO25
JTAG_TMS 13 14 GND
JTAG_TRST 15 16 86
SAI5_RX_DATA1
SAI1_TX_DATA3
SAI1_TX_SYNC
SAI5_TX_SYNC
GPIO3_IO22 (default)
(continued on the next page)