Hdmi Synchronization Parameters; Horizontal Filter And Measurements; Primary Port Horizontal Filter Measurements - Analog Devices ADV7850 Hardware Manual

Notes:
• After the part has powered up, it is recommended to wait for 1 ms before checking
ensures that the ADV7850 had sufficient time to access the internal HDCP ROM and set
•
After an AKSV update from the transmitter, it is recommended to wait for 2 ms before checking
hdcp_key_error. This ensures that the ADV7850 had sufficient time to access the internal HDCP ROM, and set hdcp_keys_read
and hdcp_key_error.
• When the ADV7850 successfully retrieves the HDCP keys and/or KSV from the internal HDCP ROM, hdcp_keys_read is set to
1 and hdcp_key_error is set to 0.
•
The I 2 C controllers for the main I
the internal registers of the ADV7850 while it reads the HDCP keys and/or the KSV from the internal HDCP ROM.
• A hardware reset (that is, reset via the RESET pin) does not lead the ADV7850 to read the KSV or the keys from the HDCP
ROM.
• The ADV7850 takes 1.8 ms to read the keys from the HDCP ROM

7.24 HDMI SYNCHRONIZATION PARAMETERS

The ADV7850 contains the logic required to measure the details of the incoming video resolution. The HDMI synchronization
parameters readback registers from the HDMI Map can be used, in addition to the STDI registers from the CP (refer to Section 9.7.2) to
estimate the video resolution of the incoming HDMI stream.
Notes:
•
The synchronization parameters are valid if the part is configured in HDMI mode via prim_mode[3:0].
• The HDMI synchronization filter readback parameters are valid even while the part free runs (refer to Section 9.12) and/or
when it is configured to process analog inputs in simultaneous mode (refer to Section 3.4) on the condition that the
measurement filters have locked.

Horizontal Filter and Measurements

7.24.1
The HDMI horizontal filter performs measurements on the DE and HSync of the HDMI stream on the selected port. The ADV7850 also
performs horizontal measurements on the background port as selected by bg_meas_port_sel[2:0]. These measurements are available in
the HDMI Map and can be used to determine the resolution of the incoming video data streams.

Primary Port Horizontal Filter Measurements

7.24.2
The HDMI horizontal filter performs the measurements described in this section on the HDMI port selected by hdmi_port_select[2:0].
Notes:
• The horizontal measurements are valid only if
• The HDMI horizontal filter is used solely to measure the horizontal synchronization signals decoded from the HDMI stream.
The HDMI horizontal filter is not in the main path of the synchronization processed by the part and does not delay the overall
HDMI data in to video data out latency.
• The unit for horizontal filter measurement is a pixel, which is the actual element of the picture content encapsulated in the
HDMI/DVI stream which the ADV7850 processes. A pixel has a duration
where:
T is the TMDS frequency
FTMDS
deep_color_ratio = 1 for 24-bit deep color
deep_color_ratio = 5/4 for 30-bit deep color
deep_color_ratio = 3/2 for 36-bit deep color
deep_color_ratio = 2 for 48-bit deep color
pixel_repetition is the number of repeated pixels in the input HDMI stream
Rev. A May 2012
2 C lines and the HDCP lines are independent of each other. It is, therefore, possible to access
de_regen_lck_raw
= ⋅
T T deep _ color
Pixel FTMDS
Equation 4: Unit Time of Horizontal Filter Measurements
hdcp_keys_read
is set to 1.
T
which is provided in
Pixel
(
⋅
_ ratio pixel _ repetition
169
ADV7850
and hdcp_key_error. This
and
hdcp_keys_read hdcp_key_error
hdcp_keys_read and
Equation 4.
)
+
1
.