Evaluation of Display GRAM Functionality

[Hank777]

Evaluation of Display GRAM Functionality
The STM32MP157F-DK2 development board is equipped with an OTM8009A display.

Link:

Display panels hardware components - stm32mpu

This IC includes GRAM storage, which theoretically supports maintaining the display output even after the MPU enters sleep mode.

Are there any available test results or evaluation conclusions regarding this?

[Hank777]

OTM8009A datasheet:OTM8030A

OTM8009A features a 1244160-byte (480 x 864 x 24 / 8) Graphic RAM (GRAM).

 

A block of RAM integrated within the LCD display controller used to store pixel data for display.

 

[Hank777]

Has anyone tested the GRAM self-refresh function under low-power conditions?

[PatrickF]

Hi ​@Hank777 

 

The STM32MP157F-DK2 hardware and associated starter package has not been optimized for low.
It might be possible to tailor SW settings to keep display available during low-power modes (I guess currently Linux will stop the associated drivers and backlight, so screen became black).

 

Nevertheless, as the display keep the image when you press and maintain the reset button, I’m confident it will be possible to do it in low power with SW adaptations (I’m not SW expert, so I let you dig into https://wiki.st.com/stm32mpu/wiki/How_to_define_your_low-power_strategy.

 

Regards.

[Hank777]

Hi ​@PatrickF 

Thank you for the valuable information; it was very helpful.

Nevertheless, as the display keep the image when you press and maintain the reset button