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CedricB
Associate
May 24, 2022
Solved

LTDC clock not oscillating

  • May 24, 2022
  • 3 replies
  • 1236 views

Hello,

I'm using an STM32H743i-Eval2, we plugged in another LCD of 1024x600 RGB888 60Hz

We set the LTDC clock at 51.2Mhz as written in the LCD datasheet. (HSE 25Mhz / 25 * 512 / 10)

We get no clock at all on Pin32 of CN20 (CLK pin on LCD connector)

The clock is correct only when LTDC clock is set to 25Mhz or lower.

Our system clock is set to 400Mhz, Peripheral Clock to 100Mhz

The onboard 32bits SDRAM CAS is set to 2.

Any clue ?

This topic has been closed for replies.
Best answer by CedricB

I forgot to setup the LTDC GPIO pins frequency to Very High instead of Low by default.

3 replies

MM..1
Super User
May 24, 2022

Debug your code is running or hard fault?

And too for your resolution simply calculated freq is around 40MHz ...

CedricB
CedricBAuthorBest answer
Associate
May 27, 2022

I forgot to setup the LTDC GPIO pins frequency to Very High instead of Low by default.

Peter BENSCH
ST Technical Moderator
May 30, 2022

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Thank you!

/Peter

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