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Senior
March 23, 2020
Question

Problem with Vsync shifting after some

  • March 23, 2020
  • 3 replies
  • 731 views

Hello,

I’m working with custom stm32f429 board to drive a 7�? tft 800x480 lcd using ltdc driver, I’ve configured ltdc for showing just a blue background stored in internal frame buffer...

pixel frequency is 33.4 mhz,

page is shown successfully but there is some thing like Vsync loosing or shifting which caused screen jump...

Please help me with this issue.

BR,

This topic has been closed for replies.

3 replies

MHaji.1Author
Senior
March 24, 2020

By the way, when i use debugging mode, after hltdc config line, every thing work fine and there is no flicking, but when i run program, flicking back again.

please help....

waclawek.jan
Super User
March 24, 2020

Try decreasing color depth.

Move stack, heap and your program's variables to the CCM RAM.

JW

MHaji.1Author
Senior
March 25, 2020

Thanks for replying,

I am using rgb565, 16 bit

i‘ve also put my stack to CCM RAM, there is no variable yet, just testing lcd...

There is nothing changed and screen flicks, randomly. As I said when it is in debug mode, after ltdc init, every thing is working well, but after running prog, flicks. Come back.

Furthermore, i put my image to sdram, and addressed it to ltdc 0xd0000000, again there is flicker and screen jumping, i’ve put scop on vsync track an i saw some misplaced pulses.