Hi, I want to disable the output free-run if no input is detected. That is, I want the ADV7842 to not output anything.
My ADV7842 output is captured by an FPGA which measures the ADV7842's output format.
I have 3 scenarios:
- This goes through the CP. I set [CPMap][0xBA][HDMI_FRUN_EN] = 0 and this appears to work. When I disconnect my HDMI cable, the ADV7842 output is completely invalid. So no problem here.
- This goes through the CP as well. The HW Manual, Section 10.13 ("CP Free-Run"), says that "The free run feature is configured automatically for analog modes." I looked carefully and I don't see a register that disables free-run in this case. When I disconnect my analog input cable, the ADV7842 continues to output the same format (blue field). I want to kill the output completely.
- This goes through the SDP. There is a register to disable free-run but it doesn't seem to work as described. When I set [SDPMap][0xDD][SDP_FREE_RUN_AUTO] = 0, the ADV7842 simply outputs a black field instead of blue. But it still outputs a valid NTSC output with proper timing. I want to disable it completely.
Let me know what you think, thanks!