I've seen the message: Using ADV7393 as black burst generator
I want to do the same, I'm using slave SD Timing Mode 1 (using HSYNC and Field), connected a 27Mhz clk and left the pixel data P[7:0] connected to GND.
But i have a problem getting the analog video output to frame align on the sync inputs. It is locked to the pulses but it starts random not locked to the Field. I've tried reseting the internal SD timing from the ADV7393 by setting bit7 from register 0x8A.
But then it randomly starts with its frame
Please refer here expert gave some suggestion about genlock https://ez.analog.com/video/f/q-a/11486/adv7184-adv7391-genlock-problems/37983#37983
And also refer here https://ez.analog.com/video/f/q…
Shifting/delaying of the external H and field pulses doesn't change the video output timing.
My i2c settings are:
0x17 0x02 // reset
0x00 0x1c // enable all DAC's
0x01 0x00 // SD only
0x02 0x24 // Set black output
0x8c 0xcb //sub carrier freq
0x80 0x11 // PAL BDGHI
0x8a 0x0a // SD Timing Slave Mode 1 Ext:Horz/Field
0x8a 0x8a // SD timing reset
0x8a 0x0a // No SD timing reset
Your question has been forwarded to the part specialist.
Any updates on this issue? I will be grateful for any help you can provide.
Checking again with experts now.
Am I correct in saying that you can get the black bar test pattern output from the part, but that initially, for the first frame or so the output timing is incorrect and then corrects itself?
This would be the expected behavior after reset/power up. It takes the encoder 1-2 frames to lock to the incoming clock and sync signals.