i.MX8M SOM Hardware User Manual

Revision and Notes

 

Disclaimer

No warranty of accuracy is given concerning the contents of the information contained in this publication. To the extent permitted by law no liability (including liability to any person by reason of negligence) will be accepted by SolidRun Ltd., its subsidiaries or employees for any direct or indirect loss or damage caused by omissions from or inaccuracies in this document. SolidRun Ltd. reserves the right to change details in this publication without prior notice. Product and company names herein may be the trademarks of their respective owners.

Introduction

This User Manual relates to the SolidRun SOM i.MX8M series, which includes:

  • Dual core ARM A53 (1.5 GHz) of the i.MX8M

  • Quad lite core ARM A53 (1.5GHz) of the i.MX8M

  • Quad core ARM A53 (1.5GHz) of the i.MX8M

Overview

The SolidRun’s SOM i.MX8M is a high-performance system on module (SOM) based on the highly integrated NXP i.MX8M family of products.

Highlighted Features

  • Ultra-small footprint SOM (47x30mm) including three board-to-board connectors (250 total pins number).

  • NXP i.MX8M SoC (supports dual, quad lite and quad versions)

    • Up to quad Cortex A53 and up to 5GHz

    • Cortex-M4 subsystem processor supports real time

    • Industry-leading audio,voice and video processing for applications

    • OpenGL ES 3.1, OpenCL 1.2, OpenGL 3.0, OpenVG and Vulkan standards

  • LPDDR4 memory in x32 configurations supports up to 4GB (Quad version)

  • Power management devices

  • Gigabit Ethernet interface based on Qualcomm Atheros 8031

  • Wi-Fi (11ac/b/g/n 2Tx2R) + BT (V4.1 LE) M.2 Type 1216 based on Qualcomm Atheros QCA6174A-5.

  • BT V5.0 based on Nordic’s nRF52832.

  • PCIe clock generator supporting

  • 4-Lanes CSI connector for direct connection to a camera.

Supporting Products

The following products are provided from SolidRun both as production level platforms and as reference examples on how to incorporate the SOM in different levels of integration:

  • HummingBoard Pulse– A board computer that incorporates the SOM retains the same Android and different Linux distributions while adding extra hardware functionalities and access to the

  • CuBox Pulse – A minicomputer that is only 2″x2″x2″ in size that runs Android and Linux with different distribution variants, use cases.

Description

Block Diagram

The following figure describes the i.MX8M blocks diagram.

Feature Summary

Following is the features summary of the SOM. Notice that some of the features are pinout multiplexed (please refer to the pin mux table below and the NXP i.MX8M data sheets):

  • NXP i.MX8M series SoC (Dual/Quad Lite/Quad ARM® Cortex™ A53 Processor, up to 1.5 GHz)

  • Cortex-M4 subsystem

  • Up to 4GByte LPDDR4 memory

  • Eight bits eMMC

  • QSPI NOR Flash memory.

  • I2C

  • HDMI 2.0a, HDMI 1.4 interface

  • 4-lanes MIPI-DSI interface

  • Two 4 lanes MIPI CSI-2 ()

  • 10/100/1000 Mbps Ethernet PHY supporting 1588 standard (PPS output)

  • Wi-Fi (11ac/b/g/n 2Tx2R) + BT (V4.1 LE) M.2 Type 1216 based on Qualcomm Atheros QCA6174A-5.

  • BT V5.0 based on Nordic’s nRF52832

  • Two USB 3.0 Host and OTG

  • Two PCIe interfaces (PCIe-1 is available only if Wi-Fi is not inuse).

  • PCIe clock

  • Four bits SD interface

  • Single eSPI

  • Up to three Synchronous Audio

  • Up to three Serial

  • Required power sources:

    • A single 5.0V interface

    • 8/3.3V to support uSD card optional IO power.

Core System Components

i.MX8 SoC Family

The i.MX8M Dual / 8M QuadLite / 8M Quad processors feature advanced implementation of a quad Arm® Cortex®-A53 core, which operates at speeds of up to 1.5 GHz. A general- purpose Cortex®-M4 core processor is for low-power processing.

The following figure describes the i.MX8 SoC’s main features (For more details refer to NXP’s i.MX8 datasheet).

i.MX8M supports three variants; the following table describes the main differences:



Memory

The i.MX8M SOM support varieties of memory interfaces for booting and data storage. The following figure describes the i.MX8M SOM memory interfaces.

LPDDR4

  • Up to 4GB memory space (Quad-Lite and Dual up to 3GB).

  • 32 Bits data

  • Up to 3200 MT/s.

  • Supports D1, D2 and D4 die chips (Two CS).

  • Support various low power modes, clock and power gated

  • Support Self-Refresh

eMMC NAND Flash

  • Up to 64GB memory

  • 8 Bits data

  • Support MMC standard, up to version 0.

  • Up to 1600 Mbps of data transfer for MMC cards using 8 parallel data lines in SDR mode.

  • Up to 3200 Mbps of data transfer for MMC cards using 8 parallel data lines in DDR mode.

  • IMX-8 uSDHC-1.

  • Can be used as BOOT NVM *

Quad Serial NOR Flash (SOM)

  • Each channel can be configured as 1/2/4-bit

  • Support both SDR mode and DDR mode

  • No reset

  • IMX-8 QSPIA/nSS0.

  • Can be used as BOOT NVM *

EEPROM (SOM)

  • 1Kb EEPROM

  • ON-Semi’s CAT24AA01TDI or compatible

  • IMX-6 I2C1

  • Address 0X50 (7 bits format)

  • Stores SOM’s

Micro-SD (Carrier)

  • Optional on Carrier board

  • IMX-8 uSDHC-1.

  • Implements 4 data

  • Support SD/SDIO standard, up to version 0.

  • Up to 400 Mbps of data transfer in SDR mode and up to 800 Mbps of data transfer in DDR mode using 4 parallel data

  • Can be used as BOOT NVM *

Serial NOR Flash (Carrier)

  • Optional on Carrier board

  • 1 bits data

  • IMX-8 eSPI2/nSS0

  • Can be used as BOOT NVM *

Please Note

All boot configuration signals are available on the SOM connector.

 

10/100/1000 MBPS Ethernet PHY

The Ethernet PHY is based on the Qualcomm / Atheros AR8031. The following figure describes the Giga Ethernet interface.

  • IMX-8 RGMII

  • IEEE 802.3 Ethernet interface for 1000BASE-T, 100BASE-TX, and 10BASE-Te.

  • Atheros AR8031

  • Supports 1588 (PPS signal).

  • 25M clock supports Synchronous

WI-FI (11AC/B/G/N 2TX2R) TYPE 1216 AND BT 5.0

The following figure describes the WI-FI and BT support in the IMX-8 SOM.

WI-FI

The WI-FI module is an M.2 1216 standard LGA module. The i.MX8 WI-FI module is Silex’s

WCBN3507A which based on Qualcomm Atheros QCA6174A-5 chip. The WI-FI main features are:

  • Operate at ISM frequency Band (2.4/ 5 GHz)

  • IEEE Standards Support 802.11ac, 802.11a, 802.11b, 802.11g and 11n

  • IMX-8 PCIe-1 interface

  • Enterprise level security supporting: WPA, WPA2

  • Support 2 transmission and 2 receiving, transmission rate can up to 867Mbps(Physical Rate) in downstream and upstream

  • USB2 connection is optional from carrier board to support BT over the M.2 module (*).

  • Global

BT 5.0

The i.MX8 SOM uses U-BLOX’s NINA-B111 module. The module is based on Nordic’s nRF52832 BT SoC. The module main features are:

  • Bluetooth

  • Advanced Serial Port

  • GATT server and

  • Open CPU with Arm® Mbed™ and Nordic

  • External

  • Global

Please note

The Silex M.2 module doesn’t support BT over UART.

MIPI CSI-2 CAMERA INTERFACE

The i.MX8 SOM supports a 4-Lanes MIPI CSI-2 interface. A 22 pins FPC connector on the SOM board enables a direct connection to a Camera supporting the CSI interface.

The connector pin-out is according to Allied Vision, a cameras manufacturer. The figure to the right describes the interface signals.

  • IMX-8 MIPI CSI channel

  • Implements all three CSI-2 MIPI layers

  • Scalable data lane support, 1 to 4 Data lanes

  • Supports high speed mode (80Mbps – 1.5Gbps) per lane, providing 4K@30fpscapability for the 4 lanes

  • Virtual Channel

i.MX8M SOM External Interfaces

General

The SOM incorporates three Hirose DF40 board-to-board headers. The selection of the Hirose DF40 is due to the following criteria:

  • Miniature (0.4m pitch)

  • Highly reliable manufacturer

  • Availability (worldwide distribution channels)

  • Excellent signal integrity (supports 6Gbps)

    • Please contact Hirose or SolidRun for reliability and test result data.

  • Mating height of between 1.5mm to 4.0mm (1.5mm to 3.0mm if using 70-pin Board- to- Board header). SR-SOM-MX6 headers are fixed, the final mating height is determined by carrier implementation.

PCIe

The i.MX8 SOM supports two PCIe interfaces. The following figure describes the PCIe interfaces.

The PCIe main features are:

  • On board clock buffer sources all PCIe interfaces, on SOM and on Carrier

  • The IMX-8 CLK2_P/N clock output feeds the PCIe clock buffer

  • PCIe-1 can be used by the WI-FI module on the SOM or other module on the carrier. It is an assembly option.

  • 5 / 2.5 / 3.0 / 5.0 / 6.0 Gbps Serializer / Deserializer.

  • Compliant with PCI Express Base Specification 2.1

  • Supports Spread Spectrum Clocking in Transmitter and Receiver

  • x1 Gen2

  • The PCIe TX signals are DC coupled by capacitors.

  • The clock are HSTL compatible, no decoupling capacitors.

USB 3.0

The i.MX8M supports two USB 3.0 interfaces. The following figure describes the USB interfaces.

The USB main features are:

  • USB 1 and USB 2 are directly connected to the connectors (No HUB).

  • The TX signals are DC coupled by capacitors.

  • Complies with USB specification rev 3.0 (xHCI compatible).

  • USB dual-role operation and can be configured as host or device.

  •  Super-speed (5 Gbit/s), high-speed (480 Mbit/s), full-speed (12 Mbit/s), and low speed (1.5 Mbit/s) operations.

  • Supports four programmable, bidirectional USB endpoints.

  • OTG (on-the-go) 2.0 compliant, which includes both device and host capability. Super-speed operation is not supported when OTG is enabled.

  • The USB 3.0 module operates in following modes:

    • Host Mode: SS/HS/FS/LS

    • Device Mode: SS/HS/FS

    • OTG: HS/FS/LS.

  • Power control signal are not part of the USB module, any available GPIO can be used.

MIPI CSI

The following figure describes the CSI interface.

  • MX8 MIPI CSI channel 1.

  • Implements all three CSI-2 MIPI layers.

  • Scalable data lane support, 1 to 4 Data lanes.

  • Supports high speed mode (80Mbps – 1.5Gbps) per lane, providing 4K@30fpscapability for the 4 lanes.

  • Virtual Channel

MIPI DSI

The following figure described the DSI interface.

The DSI main features are:

  • Implements all three DSI layers.

  • Support for Command and Video modes

  • Host Version

  • Scalable data lane support, 1 to 4 Data Lanes. (Optional bidirectional support on lane 0).

  • Support for all DSI data types and formats.

  • Virtual Channel

  • MIPI Alliance Specification for Display Serial Interface Version 1.1

Audio

The i.MX8M SOM supports up to three Audio channels, SAI1, SAI2 and SAI3. The following figure describes the audio interface.

The Audio main features are:

  • SAI1 supports 8TX and 8 RX channels.

  • SAI2 and SAI3 supports RX and TX

  • SPDIF Out.

  • Transmitter with independent bit clock and frame sync supporting 1 data line.

  • Receiver with independent bit clock and frame sync supporting 1 data line.

  • Each data line can support a maximum Frame size of 32 words.

For more details check the i.MX8M datasheet and AN.

 

HDMI

The i.MX8M supports the HDMI interface including the signal termination. The following figure describes the HDMI interface :

The HDMI main features are:

  • On board pull-up termination to support HDMI levels.

  • HDMI HPD support 5V level.

  • HDMI DDC doesn’t support PU, need to support on carrier board.

  • Up to 4Kp60 video/graphics display over HDMI 2.0a with HDCP 2.2 encryption and audio formats including Dolby Digital, DTS, TrueHD,LPCM.

For more details check the i.MX8 datasheet.

UART

The i.MX8 SOM can support up to 4 UART interfaces. The following figure describes the UART interfaces.

The UART interfaces main features are:

  • UART 1 supports TX and RX. Can be used as debug terminal.

  • UART 2 supports TX, RX, CTS and RTS. When using the RTS and CTS signals UART 4 is not available.

  • UART 3 Supports TX, RX, CTS and RTS.

  • UART 4 support TX and RX. It has an assembly options:

    • On SOM BT module.

    • Free UART on carrier board.

  • High-speed TIA/EIA-232-F compatible, up to Mbit/s.

  • 9-bit or Multidrop mode (RS-485) support (automatic slave address detection).

  • 7 or 8 data bits for RS-232 characters, or 9 bit RS-485 format.

  • Hardware flow control support for request to send (RTS_B) and clear to send (CTS_B) signals.

  • RS-485 driver direction control via CTS_B signal.

  • Auto baud rate detection (up to 115.2 Kbit/s).

  • DCE/DTE capability.

For more information check the i.MX8 datasheet.

eSPI

The i.MX8 SOM supports an eSPI interface. The following figure describes the eSPI interface.

  • MX8’s eSPI channel 2.

  • Single chip select nSS0.

  • Master/Slave configurable.

  • Polarity and phase of the Chip Select (SS) and SPI Clock (SCLK) are configurable.

I2C

i.MX8 supports up to four I2c Interfaces. The following figure describes the I2C interfaces.

The I2C main features are:

  • I2C-1 is used only on the SOM. It is connected to the SOM EEPROM, PMIC and camera FPC connector.

  • I2C-2 and I2C-3 are available on the connector by default.

  • I2C-4 is not available as default configuration; it signals are available as GPIO.

  • Multimaster operation.

  • Software programmability for one of 64 different serial clock frequencies.

  • In Standard mode, I2C supports the data transfer rates up to 100 kbits/s.

  • In Fast mode, data transfer rates up to 400 kbits/s can be achieved.

MicroSD

The MicroSD supports the following features:

  • MX8 uSDHC-1.

  • Implements 4 data bits.

  • Support SD/SDIO standard, up to version 3.0.

  • Up to 400 Mbps of data transfer in SDR mode and up to 800 Mbps of data transfer in DDR mode using 4 parallel data lines.

  • 8V or 3.3V support using SD2_VSELECT signal.

 

B2B Connector’s Signal Description

J5001

PIN

PWR

Main

GPIO

 

PIN

PWR

Main

GPIO

PIN

PWR

Main

GPIO

 

PIN

PWR

Main

GPIO

1

3V3

PMIC_ON

 

 

2

 

 

 

3

3V3

BOOT_MODE0

 

 

4

 

DSI_DN3

 

5

3V3

BOOT_MODE1

 

 

6

 

DSI_DP3

 

7

GND

GND

 

 

8

GND

GND

 

9

 

DSI_CKP

 

 

10

GND

GND

 

11

 

DSI_CKN

 

 

12

 

DSI_DN0

 

13

GND

GND

 

 

14

 

DSI_DP0

 

15

 

DSI_DN2

 

 

16

GND

GND

 

17

 

DSI_DP2

 

 

18

 

PCIE1_REF_CLKP_CN

 

19

GND

GND

 

 

20

 

PCIE1_REF_CLKN_CN

 

21

 

DSI_DN1

 

 

22

GND

GND

 

23

 

DSI_DP1

 

 

24

3V3

PCIE_nPME

gpio3.IO[5]

25

GND

GND

 

 

26

3V3

PCIe_nWAKE

gpio3.IO[12]

27

3V3

PWM1_OUT

 

 

28

3V3

USB1_SS_SEL

gpio3.IO[15]

29

3V3

UART3_TXD

gpio5.IO[27]

 

30

GND

GND

 

31

3V3

UART3_RXD

gpio5.IO[26]

 

32

 

PCIE1_TXP_C

 

33

GND

GND

 

 

34

 

PCIE1_TXN_C

 

35

 

 

 

 

36

GND

GND

 

37

3V3

UART3_CTS

gpio5.IO[9]

 

38

 

PCIE1_RXP_C

 

39

3V3

UART3_RTS

gpio5.IO[10]

 

40

 

PCIE1_RXN_C

 

41

3V3

SAI1_TXD2 (BT_CFG10)

gpio4.IO[14]

 

42

GND

GND

 

43

3V3

DSI_TS_nINT

gpio5.IO[7]

 

44

3V3

UART2_RXD

gpio5.IO[24]

45

 

 

 

 

46

3V3

UART2_TXD

gpio5.IO[25]

47

GND

GND

 

 

48

3V3

UART2_CTS

uart4.RX/gpio5.IO[28]

49

 

 

 

 

50

3V3

UART2_RTS

uart4.TX/gpio5.IO[29]

51

 

SAI1_TXD4 (BT_CFG12)

gpio4.IO[16]

 

52

GND

GND

 

53

 

WIFI_DP

 

 

54

 

CSI_P1_DN0

 

55

 

WIFI_DN

 

 

56

 

CSI_P1_DP0

 

57

GND

GND

 

 

58

GND

GND

 

59

 

CSI_P1_CKP

 

 

60

 

CSI_P1_DP2

 

61

 

CSI_P1_CKN

 

 

62

 

CSI_P1_DN2

 

63

GND

GND

 

 

64

GND

GND

 

65

 

CSI_P1_DP3

 

 

66

 

CSI_P1_DP1

 

67

 

CSI_P1_DN3

 

 

68

 

CSI_P1_DN1

 

69

GND

GND

 

 

70

GND

GND

 

J7

 

PIN

PWR

Main

GPIO

 

PIN

PWR

Main

GPIO

PIN

PWR

Main

GPIO

 

PIN

PWR

Main

GPIO

1

 

PCIE2_REF_CLKP_CN

 

 

2

 

PCIE2_RXN

 

3

 

PCIE2_REF_CLKN_CN

 

 

4

 

PCIE2_RXP

 

5

GND

GND

 

 

6

GND

GND

 

7

 

PCIE2_TXN

 

 

8

3V3

SAI3_MCLK

gpio5.IO[2]

9

 

PCIE2_TXP

 

 

10

3V3

SAI3_RXC

gpio4.IO[29]

11

GND

GND

 

 

12

3V3

SAI1_TXC

gpio4.IO[11]

13

3V3

SAI3_TXFS

gpio4.IO[31]

 

14

3V3

SAI3_TXC

gpio5.IO[0]

15

3V3

SAI3_RXFS

gpio4.IO[28]

 

16

3V3

SPDIF_TX

gpio5.IO[3]

17

GND

GND

 

 

18

3V3

IR_CAP

gpio1.IO[12]

19

 

HDMI_TXP2

 

 

20

3V3

SAI1_TXD7 (BT_CFG15)

gpio4.IO[19]

21

 

HDMI_TXN2

 

 

22

3V3

SAI1_TXD0 (BT_CFG8)

gpio4.IO[12]

23

GND

GND

 

 

24

3V3

SAI1_TXD1 (BT_CFG9)

gpio4.IO[13]

25

 

HDMI_TXP1

 

 

26

3V3

SAI3_RXD

gpio4.IO[30]

27

 

HDMI_TXN1

 

 

28

3V3

SAI1_TXD3 (BT_CFG11)

gpio4.IO[15]

29

GND

GND

 

 

30

3V3

SAI1_TXFS

gpio4.IO[10]

31

 

HDMI_TXP0

 

 

32

3V3

nWDOG

gpio1.IO[2]

33

 

HDMI_TXN0

 

 

34

 

 

 

35

GND

GND

 

 

36

3V3

SAI1_MCLK

gpio4.IO[20]

37

 

HDMI_CLKP

 

 

38

3V3

CLKO2

gpio1.IO[15]

39

 

HDMI_CLKN

 

 

40

 

 

 

41

GND

GND

 

 

42

GND

GND

 

43

3V3

HDMI_CEC

 

 

44

 

Tanya

gpio5.IO[21]

45

5V

HDMI_DDC_SCL

 

 

46

 

SAI1_RXD7 (BT_CFG7)

gpio4.IO[9]

47

5V

HDMI_DDC_SDA

 

 

48

GND

GND

 

49

5V

HDMI_HPD

 

 

50

3V3

SAI1_RXD5 (BT_CFG5)

gpio4.IO[7]

51

3V3

SAI2_TXC

gpio4.IO[25]

 

52

3V3

UART1_TXD

gpio5.IO[23]

53

3V3

SAI2_TXD

gpio4.IO[26]

 

54

3V3

UART1_RXD

gpio5.IO[22]

55

3V3

SAI2_TXFS

gpio4.IO[24]

 

56

3V3

USB1_ID

 

57

3V3

SAI2_RXD

gpio4.IO[23]

 

58

GND

GND

 

59

3V3

SAI2_MCLK

gpio4.IO[27]

 

60

 

USB2_RXP

 

61

GND

GND

 

 

62

 

USB2_RXN

 

63

3V3

SAI1_RXD6 (BT_CFG6)

gpio4.IO[8]

 

64

GND

GND

 

65

3V3

SYS_nRST

 

 

66

 

USB2_TXN

 

67

3V3

SAI1_RXD4 (BT_CFG4)

gpio4.IO[6]

 

68

 

USB2_TXP

 

69

3V3

SAI1_RXC

gpio4.IO[1]

 

70

GND

GND

 

71

3V3

SAI1_RXFS

gpio4.IO[0]

 

72

3V3

SAI1_RXD2 (BT_CFG2)

gpio4.IO[4]

73

3V3

SD2_VSELECT

gpio1.IO[4]

 

74

3V3

SAI1_RXD3 (BT_CFG3)

gpio4.IO[5]

75

GND

GND

 

 

76

GND

GND

 

77

 

HDMI_AUXP

 

 

78

3V3

SAI1_RXD0 (BT_CFG0)

gpio4.IO[2]

79

 

HDMI_AUXN

 

 

80

3V3

SAI1_RXD1 (BT_CFG1)

gpio4.IO[3]

 

J9

 

PIN

PWR

Main

GPIO

 

PIN

PWR

Main

GPIO

PIN

PWR

Main

GPIO

 

PIN

PWR

Main

GPIO

1

 

MDI_TRXN3

 

 

2

GND

GND

 

3

 

MDI_TRXP3

 

 

4

 

USB1_TXP

 

5

GND

GND

 

 

6

 

USB1_TXN

 

7

 

MDI_TRXN2

 

 

8

GND

GND

 

9

 

MDI_TRXP2

 

 

10

 

USB1_RXP

 

11

GND

GND

 

 

12

 

USB1_RXN

 

13

 

MDI_TRXN1

 

 

14

GND

GND

 

15

 

MDI_TRXP1

 

 

16

 

USB1_DP

 

17

GND

GND

 

 

18

 

USB1_DN

 

19

 

MDI_TRXN0

 

 

20

GND

GND

 

21

 

MDI_TRXP0

 

 

22

 

USB2_DP

 

23

GND

GND

 

 

24

 

USB2_DN

 

25

3V3

LED_10_100_LED_1000

 

 

26

GND

GND

 

27

3V3

LED_ACT

 

 

28

3V3

USB_H1_PWR_EN

gpio3.IO[4]

29

3V3

PPS

 

 

30

3V3

USB_OTG_PWR_EN

gpio3.IO[2]

31

3V3

I2C3_SCL

gpio5.IO[18]

 

32

3V3

ECSPI2_SS0

gpio5.IO[13]

33

3V3

I2C3_SDA

gpio5.IO[19]

 

34

3V3

DSI_EN

gpio5.IO[6]

35

GND

GND

 

 

36

GND

GND

 

37

3V3

CSI_nRST

gpio1.IO[6]

 

38

3V3

SD2_CLK

gpio2.IO[13]

39

3V3

AUD_nMUTE

gpio1.IO[8]

 

40

3V3

SD2_CMD

gpio2.IO[14]

41

3V3

CLKO_25MHz

gpio3.IO[11]

 

42

3V3

SD2_DATA0

gpio2.IO[15]

43

5V

USB1_VBUS

 

 

44

3V3

SD2_DATA1

gpio2.IO[16]

45

3V3

ECSPI2_MISO

gpio5.IO[12]

 

46

3V3

SD2_DATA2

gpio2.IO[17]

47

3V3

ECSPI2_MOSI

gpio5.IO[11]

 

48

3V3

SD2_DATA3

gpio2.IO[18]

49

3V3

ECSPI2_SCLK

gpio5.IO[10]

 

50

3V3

SD2_nCD

gpio2.IO[12]

51

3V3

I2C2_SDA

gpio5.IO[17]

 

52

5V

USB2_VBUS

 

53

3V3

I2C2_SCL

gpio5.IO[16]

 

54

3V3

SAI1_TXD5 (BT_CFG13)

gpio4.IO[17]

55

3V3

SWDCLK1

 

 

56

 

 

 

57

3V3

CLK_25M

 

 

58

 

 

 

59

3V3

SWDIO1

 

 

60

 

 

 

61

1.8/3.3V

NVCC_SD2

 

 

62

3V3

ONOFF

 

63

3V3

3V3_OUT

 

 

64

3V3

SAI1_TXD6 (BT_CFG14)

gpio4.IO[18]

65

3V3

3V3_OUT

 

 

66

 

 

 

67

3V3

3V3_OUT

 

 

68

3V3

PWM2_OUT

gpio1.IO[13]

69

3V3

3V3_OUT

 

 

70

GND

GND

 

71

5V

VIN_5V0

 

 

72

GND

GND

 

73

5V

VIN_5V0

 

 

74

GND

GND

 

75

5V

VIN_5V0

 

 

76

GND

GND

 

77

5V

VIN_5V0

 

 

78

GND

GND

 

79

5V

VIN_5V0

 

 

80

GND

GND

 

Power and Reset

The i.MX8M power is a single 5V source. It uses NXP’s PMIC and discreet power converter to source all the i.MX8M power rails. The following figure describes the i.MX8M power architecture.

The power architecture main features are:

  • Single 5V power source.

  • NXP’s PF4210 source most of the IMX-8 power rails.

  • Two discrete DC-to-DC converters source the CPU SOC and ARM powers.

  • SNVS_3V3 can’t be power by a battery (No separate input).

  • 3.3V output up to 2A (Need to calculate system and SOM power).

  • Power up sequence is supported by the PMIC configuration.

Reset

The i.MX8M POR signal is activated by the PMIC output. The following figure describes the reset architecture.

A reset can be triggered by an external reset signal (Switch) or the internal Watch-Dog. Both signals are OR to disable the VDD_SOC power source. The power source PG signal enables/disables the PMIC.

i.MX8M SOM Integration Manual

Power up sequence

The i.MX8M is source by a single 5V input. Al power sequences are supported by the SOM.

When using the SOM 3.3V output there is no need to consider its power sequence. If an external power source is used, it needs to be power according to the power sequence rules. (See IMX-8 datasheet for details)

Booting Options

Fuses Booting

The i.MX8M can boot from its internal fuses map. Booting from the fuses is enabled when the BOOT_MODE[1..0] is set to “00”.

Booting From Resistors Settings

The i.MX8M SOM can boot from different NVM according to an external resistors configuration. The boot from the resistors configuration BOOT_MODE[1..0] is set to “10”.

The available booting NVM are:

  • eMMC on uSDH1.

  • MicroSD card on uSDH2.

  • QSPI on QSPIA.

The booting signals are SAI1RXD[0..7] and SAI1TXD[0..7]. The following table describes the booting signals and its status during and after POR.

The following table describes how the booting signals need to be set to support the different booting options.

I2C Interfaces

The i.MX8 SOM uses I2C1 interface for its internal configurations. The following table describes the address mapping.

Ref.

Chip

I2C Port

Address A

Port

Address B

Description

 

 

 

 

 

 

 

U15

PMIC

1

0

0

0

1

0

0

0

RW

08H

 

IMX8 PMIC

U17

EEPROM

1

1

0

1

0

0

0

0

RW

50H

EEPROM

GPIO Interfaces

The i.MX8M SOM uses some GPIO signals for it internal controls. The following table describes the GPIO allocation.

Signal

I/O

Description

Remarks

PCIE1_nCLKREQ

gpio5.IO[20]

Input from WI-FI module

Active Low

WL_REG_ON

gpio5.IO[5]

Enable the WI-FI RF

Active High

WL_nPERST

gpio4.IO[21]

Reset the WI-FI module

Active Low

REF_CLK_32K

gpio3.IO[3]

32K clock for the WI-FI module

N.I.U.

UBLOX_RSTN

gpio5.IO[1]

Reset the BT module

Active Low

ENET_nRST

gpio1.IO[9]

Ethernet PHY reset

Active Low

ENET_WoL

gpio1.IO[10]

Ethernet Wake-Up signal

Active Low

ENET_nINT

gpio1.IO[11]

Ethernet interrupt

Active Low

PMIC_nINT

gpio1.IO[7]

PMIC interrup

Active Low

i.MX8M SOM Debugging Capability

The i.MX8M SOM supports two main debugging interfaces:

  • UART interface

  • JTAG interface

The UART interface is a null modem interface that is internally pulled up and support using UART1 TX/RX signals.

The UART interface is optional to use and mentioned here since most of the software infrastructure used in CuBox-Pulse and HummingBoard Pulse uses those two signals for debugging.

JTAG interface is on the IMX-8 SOM and is exposed as test pins on component side. Following is a snapshot of the test points and its connectivity traces:

TP-4 -> JTAG_nTRST. TP-5 -> JTAG_TDI. TP-6 -> JTAG_TMS. TP-7 -> JTAG_TCK. TP-8 -> JTAG_TDO.

i.MX8M SOM Mechanical Description

The following is a diagram of the TOP VIEW of the i.MX8 SOM.

Note the following details:

  • The carrier board must use the same footprint as in the above mechanical footprint. Since this is a TOP VIEW of the print side of the SOM i.MX8, the diagram above describes the dimensions and placement of the board-to- board headers, mechanical holes and boundaries of the SOM i.MX8, as-is.

  • J5002 is the main board-to-board header (bottom side in the diagram).

  • J8004 is the second board-to-board header (upper side in the diagram).

  • J5001 is the third board-to-board header (right side in the diagram).

  • CuBox-i design does not use the mechanical holes, since the mating strength of two Hirose DF40 pairs and the internal heat spreader is satisfactory for the design requirements.

  • In case 1.5mm mating height was chosen, then the SOM i.MX8 requirement would be that all area beneath it on the carrier will be all dedicated ONLY for the board- to-board connectivity; no other components are allowed.

  • In case higher mating is chosen, then 1.5mm should be reserved for the SOM i.MX8M. For instance, if 3.5mm mating height is chosen, then 1.5mm is dedicated to the SOM i.MX8M print side components and the remaining 2mm for the carrier components underneath the SOM i.MX8M.

Refer to SolidRun HummingBoard and CuBox Pulse design and layout, where there are examples of the main and second 80 pin header board-to- board usage.

Documentation

  File Modified

PDF File imx8m-simplified-schematics-v2.pdf

Dec 28, 2021 by SolidRun

ZIP Archive sr-imx8m-heatsink-rev1.0.zip

Dec 28, 2021 by SolidRun

File i.MX8M SOM Documentation Board & Assembly Models.rar

Dec 28, 2021 by SolidRun

SolidRun Ltd.