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ADV7611 outputs Black video after plugging HDMI cable and it does not recover

Question asked by Adrian.Aznar on Jul 14, 2014
Latest reply on Jul 21, 2014 by mattp

Hello you all,

We have been working with ADV7611 for a while (the NON-HDCP version) and we have detected the following problem: sometimes when the HDMI cable is plugged (with a YCbCr 4:2:2 1080p50 HDMI compliant signal) the video output of ADV7611 gets Black.

The source is checked that is NOT HDCP encrypted because we generate it with a HDMI video generator designed by us.

The ADV7611 is programmed to work in automatic mode, so it configures CSC based on decoded AVI Infoframes. With further research about this problem we realized that although ADV7611 detects the incoming signal as a HDMI one (HDMI_MODE_RAW = 1), the IC is not able to detect AVI infoframes, so it configures itself with the following parameters: CSC_COEFF_SEL_RB = 0x50 (RGB to YPbPr601) and HDMI_COLORSPACE = 0x00 (RGB_LIMITED), when in normal operation they should be CSC_COEFF_SEL_RB = 0x00 (CSC is Bypassed) and HDMI_COLORSPACE = 0x03 (YUV_709).

When the ADV7611 enters this state, it is not able to recover itself until we force a reset (by software, it's not necessary to pull-down the reset pin).

Looking through the API and TV/Repeater applications I have seen that some ADV7611 registers are written in order to reset some sections of this IC, which are not documented. For example: ATV_I2CWriteField8 (VRX_HDMI_MAP_ADDR, 0x5A, 0x02, 1, 1) inside HAL_RxHdmiGetInterrupts (RX_HDMI_INTERRUPTS *HdmiInts) function. This bit is not mentioned in the ADV7611 documentation.

I would like to know the following:

1.- What could be the cause of this problem. It only happens arround 1/10 times the cable is plugged. Sometimes it also occurs at the beginning, so only the initial configuration is programmed into ADV7611. The ADV7611 outputs a correct Black video with correct syncs (HS, VS and DE) in 1080p50, while the input is SMPTE Bars

2.- In case I cannot prevent this problem to happen, how I could recover the ADV7611 without resetting it.

The application we are working with is the ADI DVP Software Receiver Application Software Driver Rev. v1.55, using only the TV application.

Thank you in advance,

Adrian

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