New Tmds Frequency Detection - Analog Devices ADV7619 Reference Manual

ADV7619 Required Settings Manual

5 NEW TMDS FREQUENCY DETECTION

A change in TMDS frequency can be detected using the flow illustrated on Figure 3.
ENABLE TMDS_CLK_X_ST INTERRUPT FOR
THE HDMI PORTS THAT ARE USED
ENABLE TMDSPLL_LCK_X_ST INTERRUPT
BY SETTING TMDSPLL_LCK_X_MB1 or
TMDSPLL_LCK_X_MB2 = 1
ENABLE NEW_TMDS_FRQ_ST INTERRUPT
BY SETTING NEW_TMDS_FRQ_MB1 or
NEW_TMDS_FRQ_MB2
NO
TMDS_CLK_X_RAW
NO
TMDS_PLL_LCK_RAW
1
Where X = An active port selected by HDMI_PORT_SELECT (HDMI Map, REG 0x00 bits [3:0])
Refer to Hardware User Guide UG-237 (TMDS Measurement section) for details on register addresses.
START
1
1
1
1
IS
SET?
YES
IS
YES READ THE TMDS FREQUENCY
SET ?
TMDS FREQUENCY READ BACK VALID
Figure 3: Example algorithm to monitor changes of TMDS frequency.
TMDS FREQUENCY READ BACK
NOT VALID OR STABLE
TMDSFREQ
IS
YES
1
TMDS_CLK_X_ST
SET?
NO
IS
YES
1
TMDS_PLL_LCK_X_ST
SET?
NO
IS
YES
NEW_TMDS_FRQ_ST
SET?
NO
AND STABLE
Rev. 1.8 | Page 9 of 14
ADV7619 Reference Manual
1
CLEAR TMDS_CLK_X_ST BY
1
SETTING TMDS_CLK_X_CLR TO 1
1
CLEAR TMDS_PLL_LCK_X_ST BY
SETTING TMDS_PLL_LCK_X_CLR TO 1
CLEAR NEW_TMDS_FRQ_ST BY
SETTING NEW_TMDS_FRQ_ST_CLR TO 1
1