DS90UH948-Q1: When the LVDS CONTROL REGISTER Bit 1-0 of DS90UH948-Q1 changes from 00 to 10, the ODD and Even swing amplitudes are inconsistent.

user6263833

Part Number: DS90UH948-Q1

Dear All

Thanks in advance!~

As the title content, the following is a description of the problem, the detailed waveform can also refer to the attachment

We used DS90UH948-Q1 1-channel FPD-Link III input, Dual Link OpenLDI output mode.

Initially we set the LVDS CONTROL REGISTER Bit 1-0 to 00. When we want to increase the swing, we only set the LVDS CONTROL REGISTER Bit 1-0 to 10. The phenomenon shown in the figure occurs. The output of ODD & EVEN swing is not consistent.

We tried to compare various factors, but still didn't find the reason, please help to see if there are other registers that we have ignored, thank you very much~

over 5 years ago

0 Casey McCrea over 5 years ago

TI__Guru** 103215 points

Hello,

For setting the second output port swing, use 0x34[1:0] and select PORT1 and then change the swing control register.

Best Regards,

Casey

0 user6263833 over 5 years ago in reply to Casey McCrea

Prodigy 200 points

lvds_TI_QA_0119.XLSX

0 user6263833 over 5 years ago in reply to Casey McCrea

Prodigy 200 points

Hi~

Thank you very much for your prompt reply.

Initially we set DS90UH948-Q1 0x4B [1: 0] = 00.

When we set DS90UH948-Q1 0x4B [1: 0] = 10, DS90UH948-Q1 D0 ~ D3 & CLK1 swing = 325mV, but DS90UH948-Q1 D4 ~ D7 & CLK2 swing 176mV .

DS90UH948-Q1 0x4B [1: 0] = 11 is also be different.

Sorry for not sending the attachment yesterday, please refer to the document of 0120,which is the latest correction.

thank you very much~

0 user6263833 over 5 years ago in reply to user6263833

Prodigy 200 points

Hi~

I'm sorry that the 0120 file could not be uploaded. The basic information in the 0119 file is correct. Change No.2 one point: DS90UH948-Q1 0x4B [1: 0] = 11 The corresponding software version is reg2.

Thank you so much~

0 Casey McCrea over 5 years ago in reply to user6263833

TI__Guru** 103215 points

Hello,

As I said above, in order to change the EVEN LVDS pairs you must select PORT1 with register 0x34[1:0] and then change the 0x4B register.

Best Regards,

Casey

0 user6263833 over 5 years ago in reply to Casey McCrea

Prodigy 200 points

Hi~

Thanks for your reply
We previously set register 0x34 [1: 0] = 01, now after register 0x34 [1: 0] = 11, then adjust 0x4B, right?

Thank you so much~

0 Casey McCrea over 5 years ago in reply to user6263833

TI__Guru** 103215 points

Hello,

I have not confirmed if the two ports can be changed at the same time with 0x34[1:0] = 11, however I think at least this command sequence should work:

0x34[1:0] = 01

Adjust 0x4B

0x34[1:0] = 10

Adjust 0x4B

Can you let me know if this gives the desired results?

Thanks,

Casey

0 user6263833 over 5 years ago in reply to Casey McCrea

Prodigy 200 points

Hi,

The problem has been solved according to your guidance.

Thanks again for your quick and effective help,

thank you so much~

Aihua

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DS90UH948-Q1: When the LVDS CONTROL REGISTER Bit 1-0 of DS90UH948-Q1 changes from 00 to 10, the ODD and Even swing amplitudes are inconsistent.