DS90UB926Q-Q1: Can ds90ub926q be paired with DS90UR241?

Hi Jack,

Thank you for the reply. Can you point me to the document where it says how to configure it? I can find in DS90UR906Q datasheet how to configure it to work with DS90UR241 and in DS90UB926Q datasheet how to make it compatible with DS90UR905Q. However, the pinout for DS90UB926Q and DS90UR906Q are different and I could not find anywhere how to make DS90UB926Q work with DS90UR241. Also, with the same hardware design, can DS90UB926Q interface with DS90UB925Q, DS90UR241 and DS90UR905Q,say, in different vehicles?

Even better, can same hardware design for DS90UB928Q interface with DS90UB927Q, DS90UB925Q, DS90UR241 and DS90UR905Q?

Hi Wei,

The UR241 will output on DOUT+ and DOUT- pins. These will enter the UB926 at the RIN+ and RIN- pins. The MODE_SEL or configuration registers will need to be changed to have the UB926 receive FPD-Link II frames.

Wei Xiao said:

Also, with the same hardware design, can DS90UB926Q interface with DS90UB925Q, DS90UR241 and DS90UR905Q,say, in different vehicles?

The UB926 can interface with all the serializers you listed. Could you clarify what is meant by "in different vehicles"?

Wei Xiao said:

can same hardware design for DS90UB928Q interface with DS90UB927Q, DS90UB925Q, DS90UR241 and DS90UR905Q?

The UB928 is compatible with the UB927 and UB925 and backwards-compatible with the UR241 and UR905Q. 

Regards,

Jack

Thank you for the clarification. Please let me know if I understand correctly.

For UB926 to work with ur905, configuration registers 0x02 bit 2 and 3 should be 11. Will this setting work with both UB925 and UR905 inputs? For UB926 to work with ur241, just set 0x00 according to ur906 datasheet, bit 2 and 3 should be 10? Then will the setting of 0x02 bit 2 and 3 being 11 and 0x00 bit 2 and 3 being 10 work with UB925, UR905 and UR241? Or, should the settings be changed when the serializer used is different?

For UB928 to work with all four serializers, should the configuration registers just be set same as above?

Jack Scherlag said:

Could you clarify what is meant by "in different vehicles"?

We are designing boards to interface with Chevy OEM lvds signals. For example, 2014 to 2018 chevy 4 inch screen use UR241, 8 inch screen use UR905 or UB925, 2019 and later 8 inch screen uses UB927. We want to design a hardware to work with all those.

Another question. In different vehicles, with the same settings, sometimes the display is shifted. Are there settings in configuration registers related? horizontal position and ratio, vertical position and ration, etc

Hi Wei,

Wei Xiao said:

For UB926 to work with ur905, configuration registers 0x02 bit 2 and 3 should be 11.

Yes, register 0x02 bits 2 and 3 should be set to 1 for backwards-compatibility. 

Wei Xiao said:

Will this setting work with both UB925 and UR905 inputs? 

The UB925 is not FPD-Link II it will not work in backwards-compatibility mode. The UR905 will work in the backwards-compatibility mode.

Wei Xiao said:

For UB928 to work with all four serializers, should the configuration registers just be set same as above?

The value of the configuration registers depends on whether the serializer is a FPD-Link II device or a FPD-Link III device. Backwards-compatibility modes need to be enabled when going between FPD-Link II and FPD-Link III devices.

Wei Xiao said:

Are there settings in configuration registers related? horizontal position and ratio, vertical position and ration, etc

These devices are older FPD-Link products so video cropping/positioning is not available.

Wei Xiao said:

For UB926 to work with ur241, just set 0x00 according to ur906 datasheet, bit 2 and 3 should be 10? Then will the setting of 0x02 bit 2 and 3 being 11 and 0x00 bit 2 and 3 being 10 work with UB925, UR905 and UR241? Or, should the settings be changed when the serializer used is different?

I am not sure what you are trying to say here. Are you mentioning the I2C device register 0x00? Again, if you are using an FPD-Link III device with an FPD-Link III device you do not need to enable backwards-compatibility.

Regards,

Jack

Hi Jack,

Thank you for the reply.

I did further research and have pretty much figured out how to make ub928 or ub926 to be compatible with the serializers but ur241

Jack Scherlag said:

if you are using an FPD-Link III device with an FPD-Link III device you do not need to enable backwards-compatibility.

Not sure if you think ur241 is FPD-LINK III serializer. It's FPD-Link II serializer older than ur905 actually. Datasheet is here: https://www.ti.com.cn/document-viewer/cn/DS90UR241-Q1/datasheet/abstract#snls2311817

ur906 can be configured to be backward compatible with ur241 as described here: https://www.ti.com/document-viewer/DS90UR906Q-Q1/datasheet/serializer-and-deserializer-operating-modes-and-backward-compatibility-config-1-0-snls3133394#snls3133394

and here: https://www.ti.com/document-viewer/DS90UR906Q-Q1/datasheet/register-maps-snls3138511#SNLS3138511

However, I could not find anywhere if in backward compatible mode, ub926 or ub928 supports ur241 and if extra hardware change or configuration register change needed. That's the main question now.

Thanks.

Hi Jack,

Thank you for the fast response.

I have read section 8.3.3 in the UB926 and UB928 datasheets, but they only mentioned ur905 and ur907. That's why I questioned if ur241 works with ur926 or ur928.

So, you are saying that just use the configuration stated for ub926 or ub928 to be compatible with ur905 to make Ur241 work with them and no other changes needed, although ur906 needs configuration change to be backward compatible with ur241? If that's the case, has it been tested in real life? I ask because I did not see anywhere mentioning them being used together.

Thanks.

Hi Wei,

Wei Xiao said:

So, you are saying that just use the configuration stated for ub926 or ub928 to be compatible with ur905 to make Ur241

Yes, this will allow the UB926 or UB928 to interpret FPD-Link II frames.

Wei Xiao said:

although ur906 needs configuration change to be backward compatible with ur241?

UR906 does not need a configuration change. Both the UR906 and the UR241 are FPD-Link II devices.

Wei Xiao said:

If that's the case, has it been tested in real life?

I cannot confirm any tests of the DS90UR241 with the DS90UR906 or DS90UB926/928. All I know is that the FPD-Link III devices mentioned previously can receive input from FPD-Link II devices.

Regards,

Jack

Hi Jack,

Thank you for the reply. 

If I want to have the deserializer to feed signal to a chip accepting mipi signal input, what's the best option that works with ur905, ur241, ub925, and ub927 serializers? is there a deserializer that works directly, or what additional ic needed?

Hi Wei,

What MIPI interface does the chip accept (DSI, CSI, etc.)? The DS90UB940-Q1 outputs MIPI CSI-2 and is backwards-compatible with the UB925 and UB927.

Regards,

Jack

Jack Scherlag said:

What MIPI interface does the chip accept (DSI, CSI, etc.)?

It's CSI. Can DS90UB940-Q1 interface with UR905, UR241 directly?

Or, is there an IC bridge UR905, UR241 with UB940?

Hi Wei,

The DS90UB940-Q1 cannot interface with FPD-Link II devices such as the UR905 and UR241. I will see if there are any solutions for interfacing the UR905 or UR241, but it is not likely. The main issue is that the UR905 and UR241 run on the older FPD-Link II protocol which is not compatible with FPD-Link III. 

Regards,

Jack

Hi Jack,

Thank you for the reply. Someone recommended ur910. Can you confirm that it's compatible with UB925 and ub927 in addition to ur241 and ur905? According to section 7.1 of the datasheet, it's very promising.

www.ti.com/.../detailed-description

Just read the section again and realized that it means ub925 an ub927needs to be set in backward compatible mode for them to work with ur910. Since ub925 and ub927 are on OEM devices, unless we can set their mode through ur910, then they won't work with ur910?

Hi Jack,

Thank you for the reply. In some vehicles, the HMI uses UR905 but the DVD uses UB925. Do you know of a deserializer that works with both and outputs MIPI CSI-2? If no one IC can accomplish that, what's your recommendation on design?

Hi Wei,

The UR910 is able to work with both the UR905 and UB925 and output MIPI CSI-2.

Regards,

Jack