[ADV7480] About the value of stdi_dvalid_ch1

Question

Hi 
 Customer wants to confirm the value of stdi_dvalid_ch1 as a condition in the flow to check the video input resolution. They are considering a flow that sets the Slave Address to 0x44 (CP-MAP) and checks if the value of Register Address = 0xB1 bit[7] (stdi_dvalid_ch1) is 1. 
 We have two questions about stdi_dvalid_ch1. Q1. Stdi_dvalid_ch1 will contain the result of what was confirmed? Q2. What is the state of the input signal when Stdi_dvalid_ch1=0? 
 
 There is no description about stdi_dvalid_ch1 in the data sheet. Could you please reply as soon as possible? 
 Best Regards.

PoornimaSubramani · Accepted Answer

Hi, 
 Please find the below comments, 
 Q1. Stdi_dvalid_ch1 will contain the result of what was confirmed ? 
 Generally, STDI registers is used to measure the input format timing & in addition to the STDI HDMI Synchronization parameters read back registers can be used. 
 Q2. What is the state of the input signal when Stdi_dvalid_ch1=0 ? 
 Yes, these register(stdi_dvalid_ch1) details are not available in the "ADV748x manuals" but you can use this register(CH1_STDI_DVALID, CP Map, Address 0xB1[7] (Read Only)) Since it is mentioned in the UG-214: ADV7842 Hardware User Guide 
 Note: 
 It is recommended to check that the following read back registers are all set to 1 before reading the horizontal and vertical measurements in the HDMI/MHL Receiver: 
 &bull; de_regen_lck_raw, IO Map, Address 0x71[0] 
 &bull; v_locked_raw, IO Map, Address 0x71[1] 
 &bull; tmdspll_lck_a_raw, IO Map, Address 0x71[7] 
 &bull; stdi_dvalid_ch1, CP Map, Address 0xB1[7] 
 The horizontal and vertical measurements are valid and stable once these four read back registers are all stable and set to 1. 
 
 Thanks, 
 Poornima)

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[ADV7480] About the value of stdi_dvalid_ch1