Change Clock Source STM32F429i discovery

[TTú.1]

Hello everyone!

I'm working on a TouchGFX project on an STM32F429i discovery board

When creating project automatically, the default clock source selected in my project is HSE clock source with HCLK frequency of 168Mhz, the program works fine. But when I change the HCLK frequency to 180 Mhz nothing appears on the LCD.

What do I need to do next? Please give me some advice!

Thanks everyone!

[SofLit]

Hello,

Did you activate the overdrive mode? :

 /* Activate the Over-Drive mode */

 HAL_PWREx_EnableOverDrive();

From the datasheet:

- when VOS[1:0] = '0x11, the maximum value of fHCLK is 168 MHz. It can be extended to 180 MHz by activating the over-drive mode.

[TTú.1]

Hello @Community member​ 

Thanks for your reply!

In my project, the overdrive mode is activated. I found the error in my project located in LCD-TFT clock, if the LCD-TFT clock frequency > 17Mhz then the image displayed on LCD will be wrong. Is there any method to calculate exactly the frequency that I need?

Thank you!

[SofLit · Accepted solution]

Hello @Trần Tú​ ,

I suggest to refer to the AN4861 "LCD-TFT display controller (LTDC) on STM32 MCUs" for LTDC usage.

[TTú.1]

Thank you so much!