Note this FAQ relates to the ADV7180, ADV7182, ADV7280, ADV7280-M, ADV7281, ADV7281-M, ADV7281-MA, ADV7282 and ADV7282-M models. These devices will be referred to as ADV728x/ADV728x in this FAQ.
The easiest way of determining if the ADV718x/ADV728x has locked or lost lock to a video source is to program the INTRQ interrupt pin.
Alternatively the LOST_LOCK and IN_LOCK bits can be used to determine if the ADV718x/ADV728x has locked, or lost lock, to a video source. Note in order for the LOST_LOCK and IN_LOCK bits to work correctly the ADV718x/ADV728x must be programmed with an Analog Devices recommended script.
LOST_LOCK bit can be found at User Map, Register 0x10, Bits . IN_LOCK bit can be found at User Map, Register 0x10, Bits .See "Global Status Register" section of the ADV7180 datasheet (and ADV7182 datasheet) for more information.
The table below show the operation of the LOST_LOCK and IN_LOCK bits as the active video source is connected or disconnected.