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ADV7610 - completely disable freerun mode

Category: Hardware
Product Number: ADV7610


We are trying to completely disable the ADV7610 freerunning mode, as we do not want to receive any pixel valid when the HDMI cable is unplugged.
However, we still see valid black RGB pixels (all zeros) coming out of the ADV7610 when cable is unplugged.

Here is a part of our configuration:

0x44 (CP), 0xBA = 0x00

0x44 (CP), 0xBF = 0x10

0x44 (CP), 0xC9 = 0x2C

Is it possible to completely disable the freerun mode to avoid having any valid pixel sent from the ADV7610 when HDMI cable is unplug?

Thanks for you help,

Typos corrected
[edited by: jon510 at 9:17 AM (GMT -5) on 22 Nov 2023]
  • Hi,

    Please try setting TRI_PIX, TRI_LLC and TRI_SYNCS to '1'.

    Could you please also try to enable the below configuration for 4:2:2 24 bit SDR mode.

    98 02 FA ; YUV Conversion applied //YUV601 to YUV709 conversion applied if input is YUV601. YUV709 to YUV601 conversion applied if input is YUV709
    98 03 8A; 24 bit SDR 422 Mode 2
    98 05 28 ; AV Codes Off

    Dharani S

  • Hi,

    Thanks for your response. We do not want to tristate the output drivers since we want them to be active when an HDMI cable is plugged in... And we would like to avoid a dynamic re-configuration of these pins.

    Concerning the data format, we use 24-bit 4:4:4 SDR mode, so we don't want to change 0x98 (IO), 0x02 / 0x98 (IO) 0x03. 

    Here are the current values of these registers:

    0x98 (IO), 0x02 = 0xF2 (0b11110010)

    -> INP_COLOR_SPACE = 0b1111

    -> ALT_GAMMA = 0

    -> OP_656_RANGE = 0

    -> RGB_OUT = 1

    -> ALT_DATA_SAT = 0

    0x98 (IO), 0x03 = 0x40

    -> OP_FORMAT_SEL set to 24-bit 4:4:4 SDR mode

    0x98(IO), 0x05 = 0x28 (0b00101000)

    -> F_OUT_SEL = 0

    -> DATA_BLANK_EN = 1


    -> REPL_AV_CODE = 0

    -> OP_SWAP_CB_CR = 0

    Any other idea? Why is the freerun mode enabled although we set:

    0x44 (CP), 0xBA = 0x00
    -> HDMI_FRUN_EN = 0
    -> HDMI_FRUN_MODE = 0

    Many thanks

  • Hi,

    We have tested with the provided configuration in our lab in the ADV7610 EVB and observed the below.

    all the setting---> adv7610---> unsupported signal format (blank screen)

    tristate_llc-----> adv7610---> no signal

    Please note that, as suggested by the experts "in order to disable free run, we need to set tristate register configuration".

    Dharani S

  • Hi,

    As expected, putting all the output drivers in tristate leads to a complete desactivation of the output interfaces, even if the cable is plugged in.

    Hence, this does not solve our problem.

    As I said, we (=the FPGA) does not check if the cable is unplugged or not; we would like just to avoid to have the freerun so that the FPGA does not receive valid pixels anymore when cable is unplugged. Apparently, this seems not to be feasible...

    In any case, thanks for the help,


  • Hi,

    Eventually, we completely disabled the CP core, which solved our issue.

    0x98, 0xBF = 0x01

    -> CP_COMPLETE_BYPASS_IN_HDMI_MODE, IO, Addess 0xBF[0] = 1