Skip to main content
Visitor II
January 1, 2024
Solved

there is a delay between caling dcmi_start_dma function and data being actually received in dcmi_dr

  • January 1, 2024
  • 2 replies
  • 977 views

there is a delay between caling dcmi_start_dma function and data being actually received in dcmi_dr in stm32l4r9discovery the pixel clock is 24 mhz 

    This topic has been closed for replies.
    Best answer by KDJEM.1

    Hello @kanuz_khan ,

    If, I have understood your question correctly, yes I confirm, there is an delay between the dcmi_start_dma and the moment when the data are packed into a 32-bit data register (DCMI_DR). This delay depends on:

    - VSYNC, HSYNC, PIXCLK

    - Software optimization

    - Data formats: Monochrome, RGB, YCbCr.......

    - Length 

    - DMA configuration

    Thank you.

    Kaouthar

    2 replies

    KDJEM.1Answer
    Technical Moderator
    January 10, 2024

    Hello @kanuz_khan ,

    If, I have understood your question correctly, yes I confirm, there is an delay between the dcmi_start_dma and the moment when the data are packed into a 32-bit data register (DCMI_DR). This delay depends on:

    - VSYNC, HSYNC, PIXCLK

    - Software optimization

    - Data formats: Monochrome, RGB, YCbCr.......

    - Length 

    - DMA configuration

    Thank you.

    Kaouthar

    Technical Moderator
    March 19, 2024

    Hi @kanuz_khan ,

    Has your request been answered?

    If you need further clarification, please do not hesitate to share it :).

    Thank you.

    Kaouthar.