2133588_en-US

はい

Graphic shaking phenomenon during i.MX RT 700 operation

Dear Support team,

Device : i.MX RT700

I have observed a graphic phenomenon related to the LCD.

As the clock hand moves, the BACKGROUND image and the remaining images move together.

You can see video clip.

This phenomenon can be seen in the basic example provided by GUI GUIDER.

However, this issue does not appear on the i.MX RT 500.

In my opinion, this phenomenon requires optimization.

The test environment is as follows.

EVKIT : MIMXRT700-EVK

SCH-89280 REV A3

700-89280 REVA1

EVKIT : ZC143AC72MIPI

700-94475 REV A

SCH-94475 REV A

GUI-GUIDER : GUI Guider-1.9.1-GA

LVGL version : v9

SDK version : MCUX SDK 25.03.00

toolchain version : MCUX IDE 24.12 | ARMGC 13.2.1

Re: Graphic shaking phenomenon during i.MX RT 700 operation

It appears to be an issue related to the LCD driver or SmartWatch optimization.

After reviewing the code, I confirmed that the GPU is not the cause since LV_VGLITE (PXP) is not being used.

To investigate whether the slowdown was due to the MIPI-DSI fetching the buffer, I tested by moving the buffer to SRAM, but the same issue persisted.

Additionally, I configured the buffer with double buffering in partial refresh mode, but the issue remained.

However, when switching to full refresh mode, normal operation was observed.

In conclusion, it seems the issue arises from the MIPI DSI driver and optimization used in the Smart Watch demo not being fully refined yet.

You can resolve the issue by modifying the following code:

File: <source/lvgl_support.c>

Line 51:

#define DEMO_DISPLAY_USE_PARTIAL_REFRESH 0

Set this to use LV_DISPLAY_RENDER_MODE_FULL mode for proper functionality.

Re: Graphic shaking phenomenon during i.MX RT 700 operation