Analog Devices ADV7850 Hardware Manual page 152

en_bg_port_c, Addr 68 (HDMI), Address 0x02[2]
This control is used to set Port C in background mode to establish a HDCP link with its source, even if the port is not selected by
hdmi_port_select. This control has no effect if the port is selected by hdmi_port_select.
Function
en_bg_port_c
0 
1
en_bg_port_d, Addr 68 (HDMI), Address 0x02[3]
This control is used to set Port D in background mode to establish a HDCP link with its source even if the port is not selected by
hdmi_port_select. This control has no effect if the port is selected by hdmi_port_select.
Function
en_bg_port_d
0 
1
The ADV7850 can also perform HDMI parameter measurements and packet detection on one background port.
The following information can then be read from the background measurement parameter and background packet registers:
• bg_tmdsfreq[8:0]
• bg_tmdsfreq_frac[6:0]
•
bg_deep_color_mode[1:0]
• bg_pix_rep[3:0]
•
bg_param_lock
• bg_total_line_width[13:0]
•
bg_line_width[12:0]
• bg_total_field_height[12:0]
•
bg_field_height[12:0]
• bg_hdmi_interlaced
•
bg_hdmi_mode
• bg_audio_detected[3:0]
• bg_audio_layout
• bg_dst_double
• bg_header_requested[7:0]
• bg_header_byte1[7:0]
• bg_packet_byte1[7:0]
•
bg_valid_packet
bg_meas_port_sel[2:0], Addr 68 (HDMI), Address 0x00[5:3]
This control is used to select a background port on which HDMI measurements are to be made and provided in the background
measurement registers. The port in question must be set as a background port in order for this setting to be effective. There is no
conflict if this matches the port selected by hdmi_port_select.
Function
bg_meas_port_sel[2:0]
000 
001
010
011
Rev. A May 2012
Description
Disable port disabled unless selected with hdmi_port_select
Enable port in background mode
Description
Disable port unless selected with hdmi_port_select
Enable port in background mode
Description
Port A
Port B
Port C
Port D
152
ADV7850