Hardware Interface Specifications

Chip Block Diagram

Rockchip RK3399

Rockchip RK3399-T

Physical Photos

ROCK 4A

ROCK 4B

ROCK 4A+

ROCK 4B+

ROCK 4SE

Interface Specifications

40-PIN GPIO Header

• GPIO Voltage

RK3399 and OP1 have three IO voltage levels: 1.8V/3.0V/3.3V. The following are the default voltages:

GPIO	Voltage Level	Tolerance
GPIO3_C0	3.3V	3.465V
ADC_IN0	1.8V	1.98V
Other GPIO	3.0V	3.14V

• GPIO Interface

The ROCK 4 series features a 40-pin expansion header with color-coded pins, compatible with most sensor applications on the market.

The following pinout applies to all products in the ROCK 4 series.

caution

Not all hardware functions can be enabled simultaneously. At any given time, a pin can only be assigned one hardware function.

GPIO number	Function2	Function1	GPIO	Pin#	Pin#	GPIO	Function1	Function2	GPIO number
		+3.3V		1	2		+5.0V
71		I2C7_SDA	GPIO2_A7	3	4		+5.0V
72		I2C7_SCL	GPIO2_B0	5	6		GND
75		SPI2_CLK	GPIO2_B3	7	8	GPIO4_C4	UART2_TXD		148
		GND		9	10	GPIO4_C3	UART2_RXD		147
146		PWM0	GPIO4_C2	11	12	GPIO4_A3	I2S1_SCLK		131
150		PWM1	GPIO4_C6	13	14		GND
149		SPDIF_TX	GPIO4_C5	15	16	GPIO4_D2			154
		+3.3V		17	18	GPIO4_D4			156
40	UART4_TXD	SPI1_TXD	GPIO1_B0	19	20		GND
39	UART4_RXD	SPI1_RXD	GPIO1_A7	21	22	GPIO4_D5			157
41		SPI1_CLK	GPIO1_B1	23	24	GPIO1_B2	SPI1_CSn		42
		GND		25	26		ADC_IN0
64		I2C2_SDA	GPIO2_A0	27	28	GPIO2_A1	I2C2_CLK		65
74	I2C6_SCL	SPI2_TXD	GPIO2_B2	29	30		GND
73	I2C6_SDA	SPI2_RXD	GPIO2_B1	31	32	GPIO3_C0	SPDIF_TX	UART3_CTSn	112
76		SPI2_CSn	GPIO2_B4	33	34		GND
133		I2S1_LRCK_TX	GPIO4_A5	35	36	GPIO4_A4	I2S1_LRCK_RX		132
158			GPIO4_D6	37	38	GPIO4_A6	I2S1_SDI		134
		GND		39	40	GPIO4_A7	I2S1_SDO		135

• Notes about the 40-pin header

  • Functions marked in orange are the default functions for those pins.

  • All pins, except for power pins, are directly connected to the SoC.

  • Pins 3, 5, 27, 28, 29, and 31 are each connected to the 3.0V power supply through a 4.7K pull-up resistor.

  • Pin 7 is directly connected to the MIPI CSI pins on the board.

  • SPI

    • Pins 19, 21, 23, and 24 are also connected to the SPI flash memory pins on the board. If SPI flash memory is soldered on the ROCK 4 series board, the SPI function will not be available on the GPIO header.

  • UART

    • UART2 is enabled by default as the U-boot and Linux serial console. It can be used by selecting Rockpi4/dev/serial-console. To disable the serial console on UART2, select Rockpi4/hardware/devtree_overlays.

    • UART2 and UART4 support multiple baud rates, including but not limited to: 115200bps, 500000bps, 1500000bps, etc.

    • On some boards with onboard SPI flash memory soldered, the UART4 pins are used for SPI functionality.

  • For I2C-2 and I2C-7

    • We have tested using an I2C EEPROM device. You need to open the I2C device file first, then perform read or write operations.

eMMC Connector

Pin	Name	Pin	Name
1	VCC_1V8	2	VCC3V3_SYS
3	VCC_1V8	4	VCC3V3_SYS
5	VCC_1V8	6	VCC3V3_SYS
7	VCC_1V8	8	VCC3V3_SYS
9	VCC_1V8	10	GND
11	GND	12	eMMC_RST
13	GND	14	eMMC_CLK
15	GND	16	eMMC_CMD
17	GND	18	eMMC_D7
19	GND	20	eMMC_D6
21	GND	22	eMMC_D5
23	GND	24	eMMC_D4
25	GND	26	eMMC_D3
27	GND	28	eMMC_D2
29	GND	30	eMMC_D1
31	GND	32	eMMC_D0
33	NC	34	eMMC_DQS
35	NC	36	NC
37	NC	38	NC
39		40	NC
41		42	NC

HDMI

Pin	Name	Pin	Name
1	HDMI_TX2P	2	GND
3	HDMI_TX2N	4	HDMI_TX1P
5	GND	6	HDMI_TX1N
7	HDMI_TX0P	8	GND
9	HDMI_TX0N	10	HDMI_TXCP
11	GND	12	HDMI_TXCN
13	PORT_CEC	14	NC
15	DDC_SCL	16	DDC_SDA
17	GND	18	VCC5V0_HDMI
19	HDMI_HPD	20	GND
21	GND	22	GND
23	GND	24

MicroSD

Pin	Name
1	SDMMC0_D2
2	SDMMC0_D3
3	SDMMC0_CMD
4	VCC3V3_SYS
5	SDMMC0_CLK
6	GND
7	SDMMC0_D0
8	SDMMC0_D1
9	SDMMC0_DET_L
10	GND
11	GND
12	GND
13	GND

MIPI CSI

Pin	Name
1	VCC_CAM
2	I2C4_SCL
3	I2C4_SDA
4	CAM_MCLK
5	CAM_GPIO1
6	GND
7	MIPI_RX0_CLKP
8	MIPI_RX0_CLKN
9	GND
10	MIPI_RX0_D1P
11	MIPI_RX0_D1N
12	GND
13	MIPI_RX0_D0P
14	MIPI_RX0_D0N
15	GND

MIPI DSI

Pin	Name
1	VCC_MIPI
2	VCC_MIPI
3	GND
4	I2C_SDA_AUDIO
5	I2C_SCL_AUDIO
6	GND
7	MIPI_TX/RX_D0P
8	MIPI_TX/RX_D0N
9	GND
10	MIPI_TX/RX_CLKP
11	MIPI_TX/RX_CLKN
12	GND
13	MIPI_TX/RX_D1P
14	MIPI_TX/RX_D1N
15	GND

PCIe

Pin	Name	Pin	Name
1	GND	2	VCC3V3_PCIE
3	GND	4	VCC3V3_PCIE
5	PCIE_RX3_N	6	NC
7	PCIE_RX3_P	8	NC
9	GND	10	NC
11	PCIE_TX3N	12	VCC3V3_PCIE
13	PCIE_TX3P	14	VCC3V3_PCIE
15	GND	16	VCC3V3_PCIE
17	PCIE_RX2_N	18	VCC3V3_PCIE
19	PCIE_RX2_P	20	NC
21	GND	22	NC
23	PCIE_TX2N	24	NC
25	PCIE_TX2P	26	NC
27	GND	28	NC
29	PCIE_RX1_N	30	NC
31	PCIE_RX1_P	32	NC
33	GND	34	NC
35	PCIE_TX1N	36	NC
37	PCIE_TX1P	38	NC
39	GND	40	NC
41	PCIE_RX0_N	42	NC
43	PCIE_RX0_P	44	NC
45	GND	46	NC
47	PCIE_TX0N	48	NC
49	PCIE_TX0P	50	PCIE_PERST_L
51	GND	52	PCIE_CLKREQ_L
53	PCIE_REF_CLK_N	54	NC
55	PCIE_REF_CLK_P	56	NC
57	GND	58	NC
67	NC	68	NC
69	NC	70	VCC3V3_PCIE
71	GND	72	VCC3V3_PCIE
73	GND	74	VCC3V3_PCIE
75	GND	76	GND
77	GND

USB

• USB 2.0

Pin	Name
1	HOST0_DP
2	HOST0_DM
3	TYPEC0_DP
4	TYPEC0_DM
5	TYPEC0_ID
6	TYPEC0_U2VBUSDET
7	GND
8	HOST1_DP
9	HOST1_DM
10	USB3_DP
11	USB3_DM
12	NC
13	NC
14	GND
15	VCC_0V9
16	VCCA_1V8
17	VCC3V3_SYS

• USB 3.0

Pin	Name
1	USB3_SSTX1P
2	USB3_SSTX1N
3	USB3_SSRX1P
4	USB3_SSRX1N
5	NC
6	NC
7	NC
8	NC
9	NC
10	NC
11	NC
12	NC
13	NC
14	NC
15	NC
16	NC
17	NC
18	GND
19	VCC_0V9
20	VCC_0V9
21	VCCA_1V8
22	VCC3V3_SYS