DLPC3479: During the power-on process, dlpc3479 and dlpa3000 did not communicate with SPI

User_mgi_2023

Part Number: DLPC3479
Other Parts Discussed in Thread: DLP4710LC, , DLPA3000, DLP3010EVM-LC

My hardware combination is DLPC3479+DLPA3000+DLP4710LC.

During the power-on process, dlpc3479 did not send commands to dlpa3000 through spi, which may have caused DLPA3000 to not output DMD_VOFFSET, DMD_VBIAS, DMD_VRESET, resulting in initialization failure.

Now I have some problems with the main signals in this power-on sequence.

Qusetion1: The three signals DMD_VOFFSET, DMD_VBIAS, and DMD_VRESET require dlpc3479 to send a spi command to dlpa3000 before they can be released. I tested here and found that dlpc3479 did not send the spi command. So how should this be triggered?

Qusetion2: Use the oscilloscope to check the power-on timing of each signal of dlpc3479, but except for HOST_IRQ, which remains high, everything else conforms to this power-on timing. The HOST_IRQ signal of dlpc3479 is not pulled low. In what aspects do we need to investigate why the initialization failed?

6 months ago

0 Vivek Thakur 6 months ago

TI__Mastermind 23040 points

Hello,

Welcome to DLP forum and thank you for your interest in DLP technology.

We do have a software tool to diagnose the boot up problem. Please download "DLP-PICO-BOOT-DIAGNOSTIC-TOOL — DLP Pico Boot Diagnostic Tool) from the product folder.

DLPC3479 data sheet, product information and support | TI.com

Please follow up the instruction and let us know your findings. This tool will provide you visibility into at what stage it is failing.

Regards,

Vivek

0 User_mgi_2023 6 months ago in reply to Vivek Thakur

Prodigy 60 points

DLP-PICO-BOOT-DIAGNOSTIC-TOOL — DLP Pico Boot Diagnostic Tool，I use it, but it tell me fail. I guess this may be the failure because the three voltage signals DMD_VOFFSET, DMD_VBIAS, and DMD_VRESET are not output.

0 Mayank Khandelwal 6 months ago in reply to User_mgi_2023

TI__Genius 9971 points

From the log it seems like your DMD connection is not proper. Can you please make sure that the DMD Flex cable is connected properly with the formatter board?

Regards,

Mayank

0 User_mgi_2023 6 months ago in reply to Mayank Khandelwal

Prodigy 60 points

I reinstall dlp4710lc, I found that the printing information changed a little, but it still failed. Why did the dmd error occur?

0 Mayank Khandelwal 6 months ago in reply to User_mgi_2023

TI__Genius 9971 points

Hello,

Now the log indicate a keying failure error. Please make sure you are using DLP4710LC DMD with DLPC3479 controllers. Refer to this thread for more information - https://e2e.ti.com/support/dlp-products-group/dlp/f/dlp-products-forum/923731/faq-new-dmd-part-number-for-dlpc347x

Regards,

Mayank

0 User_mgi_2023 5 months ago in reply to Mayank Khandelwal

Prodigy 60 points

Hello,Mayank

I'm sure I'm using dlpc3479+dlpa3000+dlp4710lc, which also matches the recommended combo over here, but I'm still having the same problem!

Thanks,
Alexander

0 Maximus Rusi 5 months ago in reply to User_mgi_2023

TI__Expert 5085 points

Hi Alexander,

Please give me some time to look further into this. I will get back to you with an update soon.

Thanks,

Maximus

0 Maximus Rusi 5 months ago in reply to Maximus Rusi

TI__Expert 5085 points

Hello Alexander,

could you please provide screenshots of your schematic around the DMD HS & LS interface?

Best,

Maximus

+1 User_mgi_2023 5 months ago in reply to Maximus Rusi

Prodigy 60 points

Hi Maximus,

I referenced this diagram for my design

0 User_mgi_2023 5 months ago in reply to Maximus Rusi

Prodigy 60 points

Hi Maximus,

My schematic is shown below

Best,

Alexander

0 Maximus Rusi 5 months ago in reply to User_mgi_2023

TI__Expert 5085 points

Hi Alexander,

Do you have an DLP3010EVM-LC you can connect your optical engine to? If so I would recommend flashing it with the boot diagnostic tool, connecting your optical engine with DMD and reading the printout of the boot diagnostic tool. This way we can narrow the issue between a faulty DMD or your custom board.

Best,

Maximus

0 User_mgi_2023 5 months ago in reply to Maximus Rusi

Prodigy 60 points

Hi Maximus,

My board does not have a cypress chip, so I may not be able to use the DLP EVM GUI 3.2.0.6 software to operate it, but I can send and receive data via iic commands;
In addition, I flashed the boot diagnostic tool, and got the following results

What signals can I monitor on my side of the board?

Best,

Alexander

0 Maximus Rusi 5 months ago in reply to User_mgi_2023

TI__Expert 5085 points

Hi Alexander,

I understand you may not be able to use the GUI with your custom board, are you able to use the optical engine on your custom board with a DLP evm to determine if the issue lies on your custom board or the DMD in your optical enginer?

Previously you stated you did not get Vofs, Vrst, Vbias. Do you get the proper voltages leading up to them? Please check each of the power rails in the startup sequence according to the diagram below:

Can you also tell me the status of Host_IRQ? Does Host_IRQ ever go low or does it stay high always?

Best,

Maximus

0 Maximus Rusi 5 months ago in reply to Maximus Rusi

TI__Expert 5085 points

Hello Alexander,

Are you still having this issue? I will go ahead and close this thread for now, please respond to it if you have an update.

Best,

Maximus

0 User_mgi_2023 4 months ago in reply to Maximus Rusi

Prodigy 60 points

Hello Maximus,

Thanks for your reply.

I've just run into this problem again, and I'm not getting Vofs, Vrst, Vbias，and the IRQ kept being high.

DLPC3479 DMD_DEN_ARSTZ and DMD_LS_CLK could not be obtained.

What are these five signals related to, and how to make these signals output and obtain?

Best,

Alexander

+1 Maximus Rusi 4 months ago in reply to User_mgi_2023

TI__Expert 5085 points

Hi Alexander,

These signals are power outputs and communication lines to the DMD. Please use the following timing diagram to verify each signal syspower/proj_on and down come up accordingly. Each of these signals need to startup according to the graph for system to boot properly, if you find one of these signals do not come up, I would recommend reviewing your schematic and board around that signal to determine the cause.

Best,

Maximus

DLP®︎ products

DLP products forum

DLPC3479: During the power-on process, dlpc3479 and dlpa3000 did not communicate with SPI