AnsweredAssumed Answered

Why doesn't my ADV7800 convert 1920x1080(138MHz) of Analog RGB?

Question asked by SHIGETO on Dec 4, 2015
Latest reply on Dec 9, 2015 by SHIGETO

I'm Japanese. I'm sorry for my poor English.

I'm evaluating ADV7800.


When ADV7800 is input 1920x1080(138MHz) of Analog RGB, my ADV7800 can't detect input signal.

I can convert 1280x800,1366x768, 1920x1080(148.5MHz).


I check CP-0xB1 and 0xB2 to detect change of resolution.

But when ADV7800 is input 1920x1080(138MHz) of Analog RGB, those registers are strange.


CP-0xB1 - 0x3F

CP-0xB2 - 0xFF

↑This Value is same stat, no signal.


Hsync's pulse width is 240 ns.  ※1920x1080 (138MHz)

But I adjust Hsync's pulse width to 250 ns, ADV7800 can detect 1920x1080(138MHz) of Analog RGB.


Can't ADV7800  detect Hsync that is within the 250ns?

What do you think of this?


Best regard.


※I use following signal.


Pixel Clock : 138.5 MHz

Horizontal Active : 1920 pixels

Horizontal Front porch : 48 pixels

Horizontal Sync width : 32 pixels

Horizontal Back porch : 80 pixels

Horizontal Scan rate : 66.587kHz


Vertical Active : 1080 line

Vertical Front porch : 3 line

Vertical Sync width : 5 line

Vertical Back porch : 23 line

Vertical scan rate : 59.934 Hz