Digi ConnectCore 8M Mini Quick user guide

ConnectCore 8M Mini
Development Board
Hardware Reference Manual

Revision history—90002455
Revision Date Description
A March 2020 Initial release.
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ConnectCore 8M Mini Development Board Reference Manual 2

ConnectCore 8M Mini Development Board Reference Manual 3
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Contents
About the ConnectCore 8M Mini development board
Features and functionality 5
Placement and connectors 7
Interfaces
Power 12
DC-in connectors 12
Power architecture configuration 12
Coin cell/Supercap 12
Battery connector 13
Power and reset buttons 13
System boot 13
Debug 14
JTAG 14
SWD 14
Console ports 15
USB recovery 15
Communication 16
Gigabit Ethernet 16
RS-485 16
CAN 17
USB Host 17
USB OTG 17
Mini PCIe 17
XBee 18
Multimedia 18
HDMI, LVDS, and MIPI displays 18
MIPI-CSI camera 19
Audio 20
Storage interfaces 21
MicroSD 21
User interfaces 21
User LED 21
User button 21
ConnectCore 8M Mini Development Board Reference Manual 4

About the ConnectCore 8M Mini development board
The Digi ConnectCore 8M Mini Development Board is a system-on-module (SOM) development kit that
streamlines the prototyping of a wide range of industrial and medical applications.
Built on the i.MX 8M Mini processor with power-efficient quad ARM® Cortex®-A53 and Cortex-M4 cores,
Digi ConnectCore 8M Mini combines pre-certified wireless connectivity (802.11 a/b/g/n/ac and
Bluetooth® 5) with Digi TrustFence® and Digi Microcontroller Assist™.
Features and functionality
nPower:
l5 V input power jack connector
lBattery connector
lCoin cell connector
lOn-board supercap supporting RTC functionality
lPower and reset buttons
nBoot source configuration: eMMC, USB, microSD
nDebug:
lStandard IEEE 1149.1 JTAG interface
lSingle Wired Debug (SWD) interface for the on-module Digi Microcontroller Assist™ (MCA)
lUSB console
lUSB for system-on-module recovery
nMultimedia:
lHDMI display*.
lLVDS display with backlight control and I2C touch interface*.
lMIPI-DSI*.
lMIPI-CSI camera supporting two data lanes. Two additional data lanes are available in the
expansion connector.
nStorage:
lMicroSD card slot
nCommunication:
lGigabit Ethernet 10/100/1000 with RJ-45 connector
lx2 USB host (dual type-A)
lUSB OTG on micro AB-type connector
ConnectCore 8M Mini Development Board Reference Manual 5

About the ConnectCore 8M Mini development board Features and functionality
ConnectCore 8M Mini Development Board Reference Manual 6
lx5 GPIOs
lCAN FD (through SPI interface)
lRS-485
lPCI Express Mini Card slot supporting half- and full-size cards, with USB, PCIe and Micro-
SIM connection.
lAudio interfaces:
ox1 3.5 mm headphone jack
ox1 3.5 mm microphone jack
ox2 speaker outputs
ox1 line-out output
ox2 line-in inputs
lx2 XBee sockets, one supporting XBee cellular
lx2 SMA antenna connectors, one for the on-module antenna and another for the Mini PCIe
card
nUser interfaces:
lx2 user buttons
lx3 user LEDs
nDimensions:
l210 x 130 mm
Note * Only one display interface can be enabled at a time.

About the ConnectCore 8M Mini development board Placement and connectors
ConnectCore 8M Mini Development Board Reference Manual 7
Placement and connectors

About the ConnectCore 8M Mini development board Placement and connectors
ConnectCore 8M Mini Development Board Reference Manual 8
Connector Interface Manufacturer Manufacturer Part Number
J1 5 V power-in jack Bobbintron SCD443CCS011B00G
J2 Alternative 5 V power-in TE Connectivity 640456-2
J3 MCA power consumption - -
J4 Coin-cell Molex 53047-0210
J5 Battery connector TE Connectivity 640456-2
J6 SOM power consumption - -
J7 3V3 DVK power consumption - -
J8 1V8 DVK power consumption - -
J9 Debug - -
J10 u.FL antenna connector Hirose U.FL-R-SMT(10)
J11 SMA antenna connector Bobbintron SMA A700T
J12 Wireless MAC JTAG Samtec FTSH-105-01-F-DV

About the ConnectCore 8M Mini development board Placement and connectors
ConnectCore 8M Mini Development Board Reference Manual 9
Connector Interface Manufacturer Manufacturer Part Number
J13 u.FL antenna connector Hirose U.FL-R-SMT(10)
J14 SMA antenna connector Bobbintron SMA A700T
J15 u.FL antenna connector Hirose U.FL-R-SMT(10)
J16 Console (USB) Kycon KMMX-ABSMT5SG-30TR
J17 Console (TTL) - -
J18 MicroSD Amphenol GTFP08431BEU
J19 Mini PCIe Foxconn AS0B226-S68N-7F
J20 i.MX8M JTAG Samtec FTSH-105-01-F-DV
J21 MicroSIM Molex 78727-0001
J22 MCA SWD Samtec FTSH-105-01-F-DV
J23 CAN termination resistor - -
J24 CAN Samtec TSW-104-14-G-S
J25 RS485 termination resistor - -
J26 RS485 Samtec TSW-104-14-G-S
J27 Ethernet Xmultiple XMG-J1B2211NPA-1-DIG
J28 MIPI camera extension - -
J29 MIPI camera Amphenol SFW15S-2STE1LF
J30 MIPI display Amphenol SFW15S-2STE1LF
J31 HDMI Adam Tech HDMI-S-RA-TSMT
J32 LVDS Hirose DF14A-20P-1.25H(25)
J33 USB Host Excel Cell Electronic ESB01211000Z
J34 USB OTG Kycon KMMX-ABSMT5SG-30TR
J35 USB recovery Kycon KMMX-ABSMT5SG-30TR
J36 Force USB recovery - -
J37 Microphone input CUI Devices SJ1-3533NG
J38 Headphones output CUI Devices SJ1-3533NG
J39-J40 XBee Cellular Samtec SMM-110-02-F-S-P-TR
J41-J42 XBee user Samtec SMM-110-02-F-S-P-TR
J43 Control signals - -

About the ConnectCore 8M Mini development board Placement and connectors
ConnectCore 8M Mini Development Board Reference Manual 10
Connector Interface Manufacturer Manufacturer Part Number
J44 Wireless signals - -
J45 UARTs - -
J46 GPIOs - -
J47 SAI1 - -
J48 I2C - -
J49 Wireless signals - -
J50 Clocks - -
J51 SMA antenna connector Bobbintron SMA A700T
J52 Power rails - -
J53 Audio - -
J54 Supercap

Interfaces
The following interfaces are available on the ConnectCore 8M Mini:
Power 12
System boot 13
Debug 14
Communication 16
Multimedia 18
Storage interfaces 21
User interfaces 21
ConnectCore 8M Mini Development Board Reference Manual 11

Interfaces Power
ConnectCore 8M Mini Development Board Reference Manual 12
Power
DC-in connectors
The input voltage of the ConnectCore 8M Mini Development Board is 5 V. You can use one of two
connectors to power the entire system. Note that you can only enable one at a time.
nDC-in power jack connector
nJ2, a 2-pin, 2.54 mm pitch connector:
Pin Signal name Description
1 VIN 5 V power supply rail
2 GND Ground
An overvoltage circuit protects the board from overvoltage and overcurrent events. Downstream from
these input power protections, there are three regulators/switches for powering both the SOM and
the carrier board circuitry:
nMCA LDO (U2): This regulator generates the 3.3 V that powers the on-module MCA.
n5 V Load switch: A 5 V load switch controls the power delivery to some interfaces (CAN, HDMI,
LVDS).
n3.3 V On-board regulator (U4): This buck regulator powers the XBee and PCIe sockets.
Power architecture configuration
SOM input supply Power rail connected to Nominal operating voltage
VSYS VIN (input supply of the board) 5V
VCC_MCA Dedicated 3.3V regulator 3V (considering forward diode)
VDD_USDHC2 MUX_3V3_1V8 3.3V
VDD_ENET 1V8 1.8V
VDD_UART 3V3 3.3V
Coin cell/Supercap
A 70 mF supercap supports RTC applications. Connector J4 on the board is included for attaching a
coin-cell:
Pin Signal name Description
1 VCC_RTC Power supply for RTC
2 GND Ground

Interfaces System boot
ConnectCore 8M Mini Development Board Reference Manual 13
Note Coin-cell charger support will depend on the version of the SOM soldered to the Development
Board.
Battery connector
The development board includes one battery connector (J5):
Pin Signal name Description
1 VSYS2 Battery power supply
2 GND Ground
Power applied to this power supply feeds the part of the ConnectCore 8M Mini SOM that supports
battery applications.
Power and reset buttons
One power button (SW1) and one reset button (SW2) are included on the development board. These
buttons support the following functionality:
Button Board status Power button action Response
SW1 OFF Short press Power on
ON or SLEEP Long press for 5 seconds Power off
SLEEP Short press Wake-up
ON Short press Sleep
SW2 - Short press Reset
System boot
The ConnectCore 8M Mini supports different boot modes (see the ConnectCore 8M Mini Hardware
Reference Manual for detailed information). The development board supports these boot modes, but
some require changes to the populated components.
A quadruple switch (S1) allows you to easily swap between four different boot modes. Two of the four
switches are used for this purpose:
SW1.2 SW1.1 Description
Open Open Boot from eMMC0
Open Close Boot from fuses
Close Open Boot from microSD
Close Close Serial downloader

Interfaces Debug
ConnectCore 8M Mini Development Board Reference Manual 14
Debug
JTAG
A JTAG connector (J20, not populated by default) is available on the development board for accessing
the JTAG interface of the CPU:
Pin Signal name Description
1 1V8_SOM_EXT 1.8 V power supply
2 JTAG_TMS Mode select line
3 GND Ground
4 JTAG_TCK Clock line
5 GND Ground
6 JTAG_TDO Data output line
7 NC Not connected
8 JTAG_TDI Data input line
9 GND Ground
10 POR_B Reset line
SWD
The development board provides two options for programming and debugging the ConnectCore 8M
Mini on-module MCA:
nJ22, a 10 pin (2x5), 1.27 mm pitch connector:
Pin Signal name Description
1 VCC_MCA 3.3 V supply voltage of the MCA
2 SWD_DIO Data I/O line
3 GND Ground
4 SWD_CLK Clock line
5 GND Ground
6 NC Not connected
7 NC Not connected
8 NC Not connected
9 GND Ground
10 SYS_RESET Reset line

Interfaces Debug
ConnectCore 8M Mini Development Board Reference Manual 15
nTag Connect footprint.
Console ports
A dedicated USB micro AB-type port (J16) provides access to the two console ports of the
ConnectCore 8M Mini system-on-module:
ni.MX 8M Mini Cortex A-53 serial debug port
ni.MX 8M Mini Cortex-M4 serial debug port
The USB port is routed directly to the FTDI FT2232D bridge, which converts the USB bus into TTL
UARTs:
Debug port UART port
Cortex A-53 UART1
Cortex-M4 UART4
Note that UART4 is not connected to the FTDI chip by default. To access this UART, change the
following resistors:
nDepopulate R152 and R154
nPopulate R152 and R152
You can also access the UART ports at TTL level through the J17 connector:
Pin Signal name Description
1 3V3_DBG 3.3 V power rail
2 CONSOLE_TX CPU console port transmission line
3 CONSOLE_RX CPU console port receiver line
4 UART_M7_TX M7 console port transmission line
5 UART_M7_RX M7 console port receiver line
6 GND Ground
Default console port settings
nBaud rate: 115200
nData: 8 bit
nParity: none
nStop: 1 bit
nFlow control: none
USB recovery
The development board includes a dedicated USB micro AB-type port (J35) for recovery. This port
detects when a cable is plugged in and automatically switches the USB1 bus of the CPU from its

Interfaces Communication
ConnectCore 8M Mini Development Board Reference Manual 16
default USB Host connection to the recovery port:
Note If J36 is closed, then the USB1 bus of the CPU is forced to be connected to the recovery
connector J35.
Communication
Gigabit Ethernet
One 10Base-T/100Bae-Tx/1000Base-T Ethernet interface is fully integrated in the board through the
AR8031 Ethernet PHY. The bus is accessible through a RJ-45 connector with integrated link/activity
LEDs, as specified in the following table:
Green LED Yellow LED Link/activity status
ON OFF 10M/100M Link
BLINK OFF 10M/100M Active
ON ON 1000M Link
BLINK ON 1000M Active
RS-485
The development board supports one RS-485 half-duplex bus, available on an expansion connector
(J26):

Interfaces Communication
ConnectCore 8M Mini Development Board Reference Manual 17
Pin Signal name Description
1 3V3_SOM_EXT 3.3 V power supply
2 RS485_B RS485 B line
3 RS485_A RS485 A line
4 GND Ground
UART3 is used for this purpose, together with the LTC2862 transceiver. You can connect a 120Ω
terminator resistor to the bus by closing J25.
Note UART3 is also connected to expansion header J45. To use these lines on this connector, remove
resistors R291, R359, and R292 to avoid collision with the RS485 transceiver.
CAN
One CAN FD bus is available on the development board through connector J24:
Pin Signal name Description
1 5V 5 V power suppy
2 CAN1_H CAN high line
3 CAN1_L CAN low line
4 GND Ground
The i.MX 8M Mini CPU does not support any CAN interface, so the SPI3 bus of the CPU in combination
with the MCP2517FD controller and the TCAN1042 transceiver are used for this purpose.
A 120Ωterminator resistor can be connected to the bus by closing J23.
USB Host
Up to four USB Host interfaces are supported by the development board through the USB2514B USB
hub:
nTwo of the ports are available over a stackable dual USB A-type connector.
nOne port is connected to the Mini PCI Express slot.
nOne port is connected to the XBee Cellular socket.
USB OTG
A micro-AB type receptacle for USB OTG connection is available on the CC8M Mini development board.
This interface can operate in both Host and Device mode.
Mini PCIe
The development board provides one Mini PCI Express socket (J19) supporting USB, PCIe and I2C
connection to the ConnectCore 8M Mini module. A micro SIM socket is also connected to the Mini PCI
Express slot.

Interfaces Multimedia
ConnectCore 8M Mini Development Board Reference Manual 18
XBee
Two XBee sockets are populated on the development board. One of the sockets supports the XBee
Cellular.
Multimedia
HDMI, LVDS, and MIPI displays
The ConnectCore 8M Mini System-on-Module supports only one MIPI-DSI display interface. On the
ConnectCore 8M Mini Development Board, this MIPI-DSI display is managed so that three different
display interfaces are supported, although only one of them can work at a time.
nHDMI: The Lontium LT8912B bridge is populated on the development board to adapt the MIPI-
DSI interface to HDMI. This HDMI interface is available over a standard HDMI connector.
nLVDS: The SN65DSI83 bridge is also populated on the development board to adapt the MIPI-DSI
interface to LVDS. This LVDS is available over a 20-pin connector (J32), also supporting
backlight control and I2C touch controller:
Pin Signal name Description
1 3V3_SOM_EXT 3.3 V power supply
2 LVDS_TX0_N Data pair 0 (-) line
3 LVDS_TX0_P Data pair 0 (+) line
4 GND Ground
5 LVDS_TX1_N Data pair 1 (-) line
6 LVDS_TX1_P Data pair 1 (+) line
7 GND Ground
8 LVDS_TX2_N Data pair 2 (-) line
9 LVDS_TX2_P Data pair 2 (+) line
10 GND Ground
11 LVDS_CLK_N Clock pair (-) line
12 LVDS_CLK_P Clock pair (+) line
13 GND Ground
14 LVDS_TX3_N Data pair 3 (-) line
15 LVDS_TX3_P Data pair 3 (+) line
16 LVDS_PWM_OUT Backlight PWM (connected to MCA_IO17)
17 LVDS_I2C_SCL i.MX8M I2C2 bus clock line

Interfaces Multimedia
ConnectCore 8M Mini Development Board Reference Manual 19
Pin Signal name Description
18 LVDS_I2C_SDA i.MX8M I2C2 bus data line
19 LVDS_IRQ_N Interrupt line (connected to i.MX8M GPIO4_18)
20 5V 5 V power supply
nMIPI-DSI: the native MIPI-DSI interface of the SOM is available over a 15-pin connector (J30):
Pin Signal name Description
1 MIPI_EXT_DATA0_P Data pair 0 (+) line
2 MIPI_EXT_DATA0_N Data pair 0 (-) line
3 GND Ground
4 MIPI_EXT_DATA1_P Data pair 1 (+) line
5 MIPI_EXT_DATA1_N Data pair 1 (-) line
6 GND Ground
7 MIPI_EXT_DATA2_P Data pair 2 (+) line
8 MIPI_EXT_DATA2_N Data pair 2 (-) line
9 GND Ground
10 MIPI_EXT_DATA3_P Data pair 3 (+) line
11 MIPI_EXT_DATA3_N Data pair 3 (-) line
12 GND Ground
13 MIPI_EXT_CLK_P Clock pair (+) line
14 MIPI_EXT_CLK_N Clock pair (-) line
15 GND Ground
MIPI-CSI camera
The development board provides a MIPI camera serial interface (MIPI-CSI) over a 15-pin connector
(J29):
Pin Signal name Description
1 3V3_SOM_EXT 3.3 V power supply
2 MIPI_CSI_I2C_SDA i.MX8M I2C2 bus data line
3 MIPI_CSI_I2C_SCL i.MX8M I2C2 bus clock line
4 NC Not connected

Interfaces Multimedia
ConnectCore 8M Mini Development Board Reference Manual 20
Pin Signal name Description
5 MIPI_CSI_RESET_N Rreset line (connected to i.MX8M GPIO1_12)
6 GND Ground
7 MIPI_CSI_CLK_P Clock pair (+) line
8 MIPI_CSI_CLK_N Clock pair (-) line
9 GND Ground
10 MIPI_CSI_DATA1_P Data pair 1 (+) line
11 MIPI_CSI_DATA1_N Data pair 1 (-) line
12 GND Ground
13 MIPI_CSI_DATA0_P Data pair 0 (+) line
14 MIPI_CSI_DATA0_N Data pair 0 (-) line
15 GND Ground
By default, only two data lanes are supported. The additional two data lanes are available over an
expansion connector (J28):
Pin Signal name Description
1 MIPI_CSI_DATA3_P Data pair 3 (+) line
2 MIPI_CSI_DATA3_N Data pair 3 (-) line
3 GND Ground
4 MIPI_CSI_DATA2_P Data pair 2 (+) line
5 MIPI_CSI_DATA2_N Data pair 2 (-) line
6 GND Ground
Audio
The Maxim MAX98089 audio codec manages the audio interface on the development board. The board
provides the following audio functionality:
n3.5 mm headphone jack
n3.5 mm microphone jack
nx2 speaker outputs (left and right)
nx1 line-out output
nx2 line-in inputs
The speakers, line-out signals, and line-in signals are available over a 10-pin connector (J53):