I have found new information on my ADV7623 SYSTEM_PD bit issue so I am reposting.
So all this below behaves as expected per the 8.1 section of the ADV7623 Hardware Manual Rev B.:
Connect Sink Cable:
HP_ARC- pin: 2.78 VDC
HPD_STATE bit: HIGH (i.e. the HP_ARC- pin is high so hot plug detected)
RX_SENSE_STATE bit: HIGH (i.e. there is presence of TMDS clock terminations from the sink)
Disconnect Sink Cable:
HP_ARC- pin: 0 VDC
HPD_STATE bit: LOW (i.e. the HP_ARC- pin is low so hot plug NOT detected)
RX_SENSE_STATE bit: LOW (i.e. there is NO presence of TMDS clock terminations from the sink)
All good so far but when I when I attempt to set SYSTEM_PD to 0 (set all circuits of the HDMI transmitter to powered-up) it comes back as 1 (and I don’t get any video on the sink monitor)! I cannot set SYSTEM_PD to 0.
This is where it gets weird(er). I set HPD_OVERRIDE bit: LOW (HPD overridden) then I can change the SYSTEM_PD to 0 and I get video on the sink monitor!
Please, please, please, any thoughts why this could occur???