Analog Devices ADV7850 Hardware Manual page 156

an external controller to monitor the TMDS clock frequency.
• The tmds_pll_locked flag should be considered valid if a TMDS clock is input on the HDMI port selected via
hdmi_port_select[2:0].
• new_tmds_frq_raw
threshold
• The ADV7850 can be configured to trigger an interrupt when
tmdsfreq[8:0], Addr 68 (HDMI), Address 0x51[7:0]; Address 0x52[7] (Read Only)
This readback provides a full precision integer TMDS frequency measurement.
Function
tmdsfreq[8:0]
000000000 
xxxxxxxxx
tmdsfreq_frac[6:0], Addr 68 (HDMI), Address 0x52[6:0] (Read Only)
This readback indicates the fractional bits of the measured frequency of the PLL recovered TMDS clock. The unit is 1/128 MHz.
Function
tmdsfreq_frac[6:0]
0000000 
xxxxxxx
bg_tmdsfreq[8:0], Addr 68 (HDMI), Address 0xE0[7:0]; Address 0xE1[7] (Read Only)
This readback provides a precision integer TMDS frequency measurement on the background port selected by bg_meas_port_sel. The
value provided is the result of a single measurement of the TMDS PLL frequency in MHz. The value provided is the result of a single
measurement of the TMDS PLL frequency in MHz. This value is updated when an update request is made via bg_meas_req. This
measurement is valid only when bg_param_lock is set to 1.
Function
bg_tmdsfreq[8:0]
000000000 
xxxxxxxxx
bg_tmdsfreq_frac[6:0], Addr 68 (HDMI), Address 0xE1[6:0] (Read Only)
This readback provides a precision fractional measurement of the TMDS frequency on the background port selected by
bg_meas_port_sel. The unit is 1/128 MHz and the value is updated when an update request is made via bg_meas_req control. This
measurement is valid only when bg_param_lock is set to 1.
Function
bg_tmdsfreq_frac[6:0]
0000000 
xxxxxxx
tmds_pll_locked, Addr 68 (HDMI), Address 0x04[1] (Read Only)
This readback indicates if the TMDS PLL is locked to the TMDS clock input of the selected HDMI port.
Rev. A May 2012
can be used to monitor if the TMDS frequency on the selected HDMI port changes by a programmable
Description
Output 9-bit TMDS frequency measurement in MHz
Output 9-bit TMDS frequency measurement in MHz
Description
Output 7-bit TMDS fractional frequency measurement in 1/128 MHz
Output 7-bit TMDS fractional frequency measurement in 1/128 MHz
Description
Output 9-bit TMDS frequency measurement in MHz
Output 9-bit TMDS frequency measurement in MHz
Description
Output 7-bit TMDS fractional frequency measurement in 1/128MHz
Output 7-bit TMDS fractional frequency measurement in 1/128MHz
new_tmds_frq_raw changes from 0 to 1.
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ADV7850