GPIO Extension Interface

K1 reserves a 40-pin GPIO extension interface, using a 2.54 double-row straight insertion socket, which is convenient for enthusiasts to connect peripherals according to their own needs and expand different functions. Our system will set these IOs to some specific functions by default, but users can reconfigure them through software to make these general-purpose IOs have some special functions, because these IOs are all multi-functional multiplexed pins.

1. Pin Definition

2. Multifunctional Pin Definition List

All GPIOs can be set as general-purpose inputs or outputs, and can also be configured into more functions through the kernel. The following table shows the extended functions of each GPIO.

https://developer.spacemit.com/documentation?token=An1vwTwKaigaXRkYfwmcznTXned

Pin Number	Function 0	Function 1	Function 2	Function 3	Function 4	Function 5	Function 6	Function 7
3	GPIO[52]	R_SPI_RXD	R_UART1_RXD	R_PWM7	I2C4_SDA
5	GPIO[51]	R_SPI_TXD	R_UART1_TXD	R_PWM6	I2C4_SCL
7	PRI_TDI	GPIO[70]	AP_I2C2_SCL	DCLK <SPI_LCD>	UART5_TXD
8	GPIO[47]	R_UART0_TXD	R_CAN_TX0	R_PWM8	AP_I2C3_SCL	ONE_WIRE
10	GPIO[48]	R_UART0_RXD	R_CAN_RX0	R_IR_RX	AP_I2C3_SDA	KP_MKOUT[2]
11	PRI_TMS	GPIO[71]	AP_I2C2_SDA	DCX/DOUT1 <SPI_LCD>	UART5_RXD
12	GPIO[74]		PWM9	CS<SPI_LCD>	PCIe2_WAKEN
13	PRI_TCK	GPIO[72]	UART9_TXD	DIN<SPI_LCD>	UART5_CTS_N
15	PRI_TDO	GPIO[73]	UART9_RXD	DOUT0 <SPI_LCD>	UART5_RTS_N
16	GPIO[91]	MN_CLK2	VCXO_OUT	DSI_TE	R_I2C0_SCL
18	GPIO[92]	MN_CLK	PWM7		R_I2C0_SDA
19	GPIO[77]	SPI2_TXD	SPI3_TXD	AP_I2C3_SCL	UART8_CTS_N	R_PWM0	KP_MKOUT[2]
20	GPIO[49]	R_SPI_SCLK	R_UART1_CTS_N	R_PWM4	R_I2C0_SCL	KP_MKIN[3]
21	GPIO[78]	SPI2_RXD	SPI3_RXD	AP_I2C3_SDA	UART8_RTS_N	R_PWM1	KP_MKIN[3]
23	GPIO[75]	SPI2_SCLK	SPI3_SCLK	CAN_TX0	UART8_TXD	AP_I2C4_SCL
24	GPIO[76]	SPI2_FRM	SPI3_FRM	CAN_RX0	UART8_RXD	AP_I2C4_SDA
26	GPIO[50]	R_SPI_FRM	R_UART1_RTS_N	R_PWM5	R_I2C0_SDA	KP_MKOUT[3]
27	GPIO[39]	GMAC1_TX_D3	I2C3_SDA	R_I2S3_LRCK	PWM9
28	GPIO[38]	GMAC1_TX_D2	I2C3_SCL	R_I2S3_SCLK	PWM8
29	GPIO[29]	GMAC1_RXDV	UART1_TXD	PWM1	PCIe0_PERSTN
31	GPIO[30]	GMAC1_RX_D0	UART1_RXD	PWM2	PCIe0_WAKEN
32	GPIO[34]	GMAC1_RX_D3	UART4_RXD	PWM4	PCIe1_CLKREQN
33	GPIO[31]	GMAC1_RX_D1	UART1_CTS_N	32K_OUT	PCIe0_CLKREQN
35	GPIO[32]	GMAC1_RX_CLK	UART1_RTS_N	MN_CLK	PCIe1_PERSTN
36	GPIO[35]	GMAC1_TX_D0	UART4_CTS_N	PWM5	PCIe2_PERSTN
37	GPIO[33]	GMAC1_RX_D2	UART4_TXD	PWM3	PCIe1_WAKEN
38	GPIO[46]	GMAC1_CLK_REF			PWM16
40	GPIO[37]	GMAC1_TX	PWM7		PCIe2_CLKREQN

Remarks:

Voltage

All 3.3V, 5V, and ground on the board are not configurable, and all remaining pins are 3.3V, that is, the input and output of the GPIO are 3.3V. Of course, these pins are not 3.3V from the chip end, but all IOs are converted to 3.3V through level conversion.

Input and Output

The high level of the GPIO is set to 3.3V, and the low level is 0V.