[ADV8005]SPI loop through is not possible

Hi
I'm using ADV8005 on my application board.
I use SPI flash (MT25QL128ABA) for OSD and connected to SPI2.
MCU(STM32F4) connected to SPI1 and set SPI loop through, but SPI-SCK does not output to SPI flash from the SPI2 port.
Is there something wrong with the following settings?

0x1AB6 = 0x20
0x1ACD = 0x4B
0x1ACE = 0x00 or 0xFF
0x1BD3 = 0xF0

Thank you.

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  • Hi,

      By default, the SPI ports are set in manual mode for the SPI which means the SPI pins are tristated (input). To make the SPI ports operational, the following register bits must be configured to automatic mode, So 0x1ACE register should configure as 0x00(Auto).

      Also refer figure88 for SPI loop back mode connection.

    Thanks,

    Poornima

  • Hi,

    Thank you for answering.
    I tried with register setting 0x1ACE = 0x00, but no SCK was output.
    Are there any other registers that need to be configured to enable SPI?
    Also, is there an order to set the registers?
    The hardware is directly connected to the MCU --- (SPI1) ADV8005 (SPI2) --- SPI flash, like the EVM.
    Do any pins need pull-up or pull-down settings for SPI use?

    I investigated further.
    MISO2 and CS2 are output with SPI loop-through setting.
    Only SCK2 is not output.
    There is no doubt about the pin assignment.
    SCK2 (A9)
    MOSI2 (B9)
    MISO2 (B10)
    CS2 (A10)
    There are no disconnections or short circuits in the wiring. I don't understand at all.

    Thank you.

Reply
  • Hi,

    Thank you for answering.
    I tried with register setting 0x1ACE = 0x00, but no SCK was output.
    Are there any other registers that need to be configured to enable SPI?
    Also, is there an order to set the registers?
    The hardware is directly connected to the MCU --- (SPI1) ADV8005 (SPI2) --- SPI flash, like the EVM.
    Do any pins need pull-up or pull-down settings for SPI use?

    I investigated further.
    MISO2 and CS2 are output with SPI loop-through setting.
    Only SCK2 is not output.
    There is no doubt about the pin assignment.
    SCK2 (A9)
    MOSI2 (B9)
    MISO2 (B10)
    CS2 (A10)
    There are no disconnections or short circuits in the wiring. I don't understand at all.

    Thank you.

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