TFP401: Problem interfacing TFP401 to DLPC3439

Yun-Seok Cho

Intellectual 440 points

Part Number: TFP401
Other Parts Discussed in Thread: DLPC3439, DLP4710

Hello!

I have designed my own PCB which is based on DLPDLCR4710EVM.

Instead of ITE6801, I used a TFP401 as a HDMI decoder not including voice.

The source of HDMI is output of desktop computer video card.

And the resolution of HDMI is a full HD of 1920 x 1080.

I have a problem interfacing the TFP401 to DLPC3439.

As the attached image, the displayed image is not good.

The half of image is normal and the other is abnormal.

I have posted about this problem as like the below link.

https://e2e.ti.com/support/dlp/f/94/t/741486

The conclusion of this post is that there is no problem interfacing DLPC3439 to DLP4710.

But I have no confidence between TFP401 and DLPC3439.

According to the TFP401 datasheet, it shows that the TFP401 supply WUXGA resolution.

What I want to know is that the TFP401 is a proper decoder for interfacing with the DLPC3439 in full HD mode.

I'd like to approach this problem in a view of TFP401.

Please, help me to solve this problem.

Thanks!

Regards

Yun-Seok Cho

over 5 years ago

0 Ikechukwu Anyiam over 5 years ago

TI__Mastermind 35130 points

Hi Yun-Seok,

Have you checked the pin-mapping between the TFP401 and DLPC3439? Can you share your schematic with me at i-anyiam@ti.com?

Regards,
I.K.

0 Yun-Seok Cho over 5 years ago in reply to Ikechukwu Anyiam

Intellectual 440 points

Hi Anyiam,

Yes. I have checked the pin-mapping between TFP401 and DLPC3439.

But I couldn't find out any problem.

On my own board, I'm using two of DLPC3439.

The master and slave of DLPC3439 are sharing the same signals from TFP401.

The signals are like below.

1. Data : 24bit

2. HYSNC, VSYNC, ODCK, DEN

Am I right?

I sent the schematic by your e-mail.

Thank you for your time!

Regards

Yun-Seok Cho

0 Ikechukwu Anyiam over 5 years ago in reply to Yun-Seok Cho

TI__Mastermind 35130 points

Hi Yun-Seok,

The pin mapping looks okay. Other than that the issue may be with HSYNC/VSYNC on one half of the image. From the schematic it looks like the TFP401 is driving 2x DLPC3439, so one of them is likely not getting the correct timing. This would not be an issue with the TFP401, however, as it is just passing the signals through. I recommend investigating HSYNC/VSYNC for irregularities.

Regards,
I.K.

0 Yun-Seok Cho over 5 years ago in reply to Ikechukwu Anyiam

Intellectual 440 points

Hi Anyiam,

Thanks for your answer.

As you recommend me, I'll try to investigate the signal of HSYNC/VSYNC.

Regards

Yun-Seok Cho

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TFP401: Problem interfacing TFP401 to DLPC3439