Analog Devices ADV8003, Руководство по оборудованию

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ADV8003 Hardware Manual
Rev. B, August 2013 285
6.12.4. edid_tries Control
edid_tries[3:0] can be used to set the number of times the Tx EDID/HDCP controller will try to read the sink EDID after a failure. Each
time an EDID read fails with an I
2
C Not Acknowledged (NACK), this value of edid_tries[3:0] is decremented. Once the edid_tries[3:0]
reaches the value 0, the Tx EDID/HDCP controller will not attempt to read the EDID until edid_tries[3:0] is set to a value other than 0.
This could be used if a sink asserts high its HPD signal before the DDC bus is ready, resulting in several NACKs as the ADV8003 attempts
to read the EDID.
edid_tries[3:0] , TX2 Main Map, Address 0xF4C9[3:0]
This signal is used to control the number of times that the EDID read will be attempted if unsuccessful.
Function
edid_tries[3:0] Description
xxxx Number of time the EDID/HDCP controller attempts to read the EDID
6.12.5. EDID Reread Control
If the EDID data from the sink is read in and the host determines that the data needs to be reread, edid_reread can be set from 0 to 1, and
the current segment set via edid_segment[7:0] will be reread. Rereading the sink EDID may be useful, for example, if the host finds that
one EDID checksum read from the sink is invalid.
Note:
It is also possible to reread the EDID from the sink by toggling the Tx core power down system_pd from 0 to 1.
edid_reread
, TX2 Main Map,
Address 0xF4C9[4]
This bit is used to request the EDID controller to reread the current segment if toggled from 0 to 1 for 10 times consecutively.
Function
edid_reread Description
0  No action
1 Request EDID/HDCP controller to read EDID
6.13. HDCP HANDLING
6.13.1. One Sink and No Upstream Devices
The ADV8003 has a built-in controller, the Tx EDID/HDCP controller which handles HDCP transmitter states, including handling
downstream HDCP repeaters. To activate HDCP from a system level, the host controller needs to set hdcp_desired to 1 and
frame_encryption_en to 1. This informs the ADV8003 that the video stream it outputs should be encrypted. The ADV8003 takes control
from there and implements all the remaining tasks defined by the HDCP 1.4 specification.
Before sending audio and video, the BKSV of the downstream sink should be compared with the revocation list which is compiled by
managing System Renewability Messages (SRMs) provided on the source content (for example. DVD, Blue-ray Disc), and the
bksv_flag_int interrupt bit should be cleared. After the HDCP link is established between the ADV8003 and the downstream sink, the
system controller should monitor the status of HDCP by reading enc_on every two seconds. The Tx EDID/HDCP controller error
interrupt will activate and hdcp_error_int will be set to 1 if there is an error relating to the controller. The meaning of the error can be
determined by checking hdcp_controller_error[3:0] .
bksv_flag_int
, TX1 Main Map,
Address 0xEC97[6]
This bit is used to readback and control the BKSV Flag interrupt.