Chapter 6
Board serial connections
This section describes connections between MIMXRT685-EVK on-board serial peripherals and connectors for use with off-board
devices.
6.1 USB high-speed port
The board incorporates micro AB connector for of USB0 (High Speed, connector J7) port of the MIMXRT685-EVK. USB0 port
can operate as a device or a host.
The resistor divider on the VBUS pin (R54 and R55) should be depopulated if user chooses to use the VBUS_VALID comparator
to monitor the VBUS supply for a host mode application.
The power must be supplied to the board via the external power-only USB connector (J6) when this USB port is
configured for host operation.
NOTE
For further details, please refer to the High Speed Device/Host Controller on the User Manual.
6.2 USART header
Header J16 is provided as a convenient way to use the USART with a serial to USB cable. Flexcom 0 ports (
P0_1
and
P0_2
) are
used for this feature, since these ports are assigned for USART ISP mode.
These ports are shared with the Link2 debug probe (LPC4322) and PMod connector. When using this header, ensure that there
is no conflicting device connected to the PMod connector and that jumper JP21 [2-3] is set to disable the connection to the Link2.
6.3 I3C header
The MIMXRT685-EVK provides a header (J18) to easily interface with an I3C serial interface.
6.4 Flexcomm header
The MIMXRT685-EVK provides a Flexcomm interface (J47) with up to eight configurable universal serial interface modules. Each
module can be configured as: USART, I
2
C Bus, SPI Interface or I2S interface for digital audio.
NXP Semiconductors
i.MX RT685 Evaluation Board, Rev. 0, March 20 2020
User's Guide
19 / 31