AnsweredAssumed Answered

ADV7623 - DVI and HDMI mode switching

Question asked by SS963 on May 11, 2017
Latest reply on May 19, 2017 by SS963

Hi,
We've a custom board with ADV7623, and its been working fine with HDMI displays but recently we needed to support some DVI displays and in ADV7623's design files it mentions that it can switch to DVI signalling

---------------- snip from Section 8.2 - HW Ref Manual --------------

"The Tx section supports the transmission of both HDMI and DVI streams. The type of stream the
ADV7623 transmits is set via the bit HDMI_MODE_SEL. In DVI transmission mode no packets
will be sent, and all registers relating to packets and InfoFrames will be disregarded. The current
transmission mode can be confirmed by reading the bit HDMI_MODE."

--------------------------- snip end ---------------------------

--------------------- snip from page 85 - HW Ref Manual---------------------

"Background port HDMI/DVI status for a background HDMI port determined by
BG_MEAS_PORT_SEL[1:0]. The readback provides the HDMI/DVI mode status and is
updated when an update request is made via the BG_MEAS_REQ control bit. This
measurement is only valid when BG_PARAM_LOCK is set to 1."

--------------------------- snip end ---------------------------

 

So can you verify my understanding that to switch dynamically between HDMI and DVI displays on TX side, I'll have to do following steps

1. BG_MEAS_PORT_SEL[1:0]

2. BG_MEAS_REQ

3. Wait for BG_PARAM_LOCK

4. Read HDMI MAP Reg 0xEB[0]

5. Set TX MAIN MAP 0xAF[1] accordingly

6. HDMI_PORT_SELECT[1:0]

 

Also is this correct method to verify that sink is DVI or HDMI?

 

I'm using above steps and sometimes I get DVI on step 4 and other times HDMI.

 

P.S. I've a another question too that needs update: ADV7623 - TMDS PLL Lock Reset 

Outcomes