Thank you for your response. I was able to monitor the mentioned bits. The V_LOCKED_RAW and TMDS_LCK_x_RAW seem to be set all the time. Meanwhile, V_LOCKED_ST should be set only when V_LOCKED_RAW changes. I've found out, that V_LOCKED_ST becomes set again and again. I clear that bit in the interrupt handler.
It seems, that the IC loses and regains the V_LOCKED_RAW faster than I can read out the registers.
During this test, there were no switches on the HDMI input, the chip got the same signal all the time.
I think, that the ADV7619 is not able to lock on the incoming signal correctly. Do you have any idea, what should I do in this case?
Thank you,
Arpad Maroti