SN75DP130: panel screen blinking issue

David

When you try to swap the cable, (MB to front panel board), is this the cable you are swapping?

Cable length(MB-front panel board): ~33cm(100-ohm diff UL10064 AWG#32)

What is the other cable you used that causing the flicking to go away?

Are you able to run the DP electrical compliance? If not, do you have a DP AUX monitor that can capture AUX link training traffic?

Thanks

David

Hi David

thank for reply, please refer my reply as below, we assume it is compatible issue if we use marginal cable

currently we are not sure our current setting is ideal or not ? therfeforce, it is why we ask your Q1 and Q2. 

Q1: as below is our EQ configuration setting ,is it adaptive mode(low-rang EQ Gain) for our current setting??
Q2: as your experience,what EQ Gain(high-rang or Low-range) is suitable ??

When you try to swap the cable, (MB to front panel board), is this the cable you are swapping?

Cable length(MB-front panel board): ~33cm(100-ohm diff UL10064 AWG#32)

-->yes

What is the other cable you used that causing the flicking to go away?

-->we change the same one

Are you able to run the DP electrical compliance? If not, do you have a DP AUX monitor that can capture AUX link training traffic?\

-->we have run the electrical compliance on EVT stage ,the result is pass and we  will re-measure electrical compliance again while use defect cable

David

For question 1, please refer to Table 1 of the SN75DP130 datasheet. For ADDR_EQ VIL and CAD_SNK VIL, the equalizer is fixed but will change the equalization level base on the link training level. 

For question 2, it is system dependent. But if you swap to another cable and can get the flicking to go away and cables are the same, it sounds like you have a bad cable. 

Thanks

David 

Hi David

thanks for reply,please check as below

For question 2, it is system dependent. But if you swap to another cable and can get the flicking to go away and cables are the same, it sounds like you have a bad cable.

-->the flicking symptom is not always appear, it is easy to reproduce while system burn in on chamber(TA:40 degree),we know the defect Cable have marginal signal quality,

   but if DP130 have unsuitable EQ setting plus defect Cable , i think  our system will easy  to occur data corruption,  it is why we would like to ask,

as use your  other I/F part experience do you have reference data similar as below

(SATA redriver(sn75lvcp601), PCIe repeater(ds80pci402) for example)

David

Similar data is in section 7.8 of the DP130 datasheet. 

With the marginal cable, I can't say for sure the root cause of the flicking issue is the equalizer setting. Do you have an AUX monitor that can capture the link training progress? This should give us more insight where the issue is.

With EQ_I2C_ENABLE bit set to 0, the equalizer setting is fixed based on the snoop value of the link training. You could try to set the EQ_I2C_ENABLE bit to a 1, and then manually change the EQ setting to see if it improves the flicking behavior.

Thanks

David