NXP Semiconductors

UM12262

FRDM-IMX91 Board User Manual

• SWCLK (serial wire clock)

• SWDIO (serial wire data input / output)

The SWD connector P14 is shown in Figure 3.

2.16.2 USB debug interface

The i.MX 91 applications processor has six independent UART ports (UART1 – UART6). On the FRDM-IMX91

board, UART1 is used for Cortex-A55 core. A single chip USB to dual UART is used for the debug purpose. The

part number is CH342F. You can download the driver from WCH Website.

After installing the CH342F driver, the PC / USB host enumerates two COM ports connected to the P16

connector through a USB cable:

• COM Port 1: Cortex-A55 system debugging

• COM Port 2: Reserved

You can use the following terminal tools for debugging purposes:

• Putty

• Tera Term

• Xshell

• Minicom>=2.9

To debug under Linux, make sure CH342F Linux driver is installed.

Table 21 describes the required settings.

Data rate

115,200 Baud

Data bits

8

Parity

None

Stop bits

1

Table 21. Terminal setting parameters

The USB debug connector P16 is shown in Figure 3.

2.17 Board errata

No board errata.

3 Working with accessories

This section describes how a connection can be established between with the FRDM-IMX91 board and

compatible accessory boards.

3.1 5-inch Tianma LCD

TM050RDH03-41 is a 5'' TFT LCD display with 800x480 resolution. This industrial-grade display uses an RGB

interface without a touch panel. This display module connects to the FRDM-IMX91 through the EXPI 2x20-pin

connector (P11).

UM12262

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User manual

Rev. 3.0 — 22 April 2025

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