Horizontal Filters And Measurements; Horizontal Filter Locking Mechanism; Horizontal Filter Measurements - Analog Devices Advantiv ADV7604 Hardware Manual

• When the HDMI synchronization filters II are used, the synchronization readback parameters
are valid even while the part free runs (refer to Section 10.13) and/or when it is configured to
process analog inputs in simultaneous mode (refer to Section 3.8) on the condition that the
measurement filters have locked.
• The HDMI vertical and horizontal filters I do not support HDMI streams having no VSync or
HSync front porch. It is recommended to use the STDI registers in order to estimate the video
resolution of these non standard streams.
• The HDMI vertical filters II do no support HDMI streams having no VSync front porch. The
HDMI horizontal filters II do support HDMI streams having no HSync front porch. It is
recommended to use the STDI registers in order to estimate the video resolution of these non
compliant streams.

7.15.1 Horizontal Filters and Measurements

The HDMI horizontal filters perform measurements on the DE and HSync of the HDMI stream.
These measurements are available in the HDMI Map and can be used to determine the resolution of
the incoming video data. Only one filter can be activated at once via NEW_TMDS_PARAM.

7.15.2 Horizontal Filter Locking Mechanism

The locking/unlocking mechanism of the HDMI DE/HSync filter is as follows:
• HDMI DE/HSync filter I locks if the following two conditions are met:
The DE transitions occur at the exact same pixel count for 8 consecutive video lines
The HSync transitions occur at the pixel count with a variation of ±2 pixel clocks for 8
consecutive video lines
• HDMI DE/HSync filter I unlocks if the following two conditions are met:
The DE transitions occur in different pixels count for 15 consecutive video lines
The HSync transitions occur in different pixels count with a variation higher than +/- 2
pixels for 15 consecutive video lines
• HDMI DE/HSync filter II locks if the following two conditions are met:
The DE transitions occur at the exact same pixel count for 8 consecutive video lines
The HSync transitions occur at the exact pixel count for 8 consecutive video lines
• Both HDMI DE/HSync filters II unlocks if either of the two following conditions are met:
The DE transitions occur in different pixels count for 15 consecutive video lines
The HSync transitions occur in different pixels count for 15 consecutive video lines

7.15.3 Horizontal Filter Measurements

The HDMI horizontal filter selected by
described in this section.
Rev. F August 2010
NEW_TMDS_PARAM
125
performs the measurements
ADV7604