ADV7842  How can I use 3D_Comb (TBC is sttoped) with 64MB SDRAM?

Hi Bogey,

Some questions for you:

* Which evaluation board are you using?

* Which memory devices are you testing?

* How are you testing with different memory devices?

-Matt

Hi Matt,

Thank you for your attention.

Here is my answer.

If you have any more question, please let me know.

>* Which evaluation board are you using?

Ans,h

Please see attached picture.  I used that board.

>* Which memory devices are you testing?

Ans,

Memory on the board.

Samsung 128MB DDR

>* How are you testing with different memory devices?

I did not changed actual momory. 

I just changed RAM size registers in ADV7842

I changed bellows registers.

94 75 0A ;add-yt(SD-RAM 64Mb)

94 74 00 ;add-yt(SD-RAM 64Mb)

94 79 33 ;add-yt(SD-RAM 64Mb)

94 6F 01 ;add-yt(SD-RAM 64Mb)

94 60 01 ;add-yt(SD-RAM 64Mb)

94 7A A5 ;add-yt(SD-RAM 64Mb)

94 7B 8F ;add-yt(SD-RAM 64Mb)

Regards,

Bogey

Hi Bogey,

That photo shows the EVAL-ADV7842-7511. That board uses Samsung K4H561638J for ADV7842 SDRAM. It is 256Mbit (32Mbyte).

The software/scripts for this board were designed for this memory device. You should not have to modify it.

-Matt

Hi, Matt.

Let me explain my situation.

My system has 64Mbit SDRAM.

When I use 3D_Comb (TBC is sttoped), My system have same issue as EVAL-ADV7842-7511.

My sytem and EVAL-ADV7842-7511 have same issue at 3D_Comb with 64Mbit setting.

I would like to know how I can fix issue 3D_Comb with 64Mbit setting.

If you need any more information or any data, please let me know.

Regards,

Bogey

Hi Bogey,

Earlier you said that you were writing the following:

94 75 0A ;add-yt(SD-RAM 64Mb)

94 74 00 ;add-yt(SD-RAM 64Mb)

94 79 33 ;add-yt(SD-RAM 64Mb)

94 6F 01 ;add-yt(SD-RAM 64Mb)

94 60 01 ;add-yt(SD-RAM 64Mb)

94 7A A5 ;add-yt(SD-RAM 64Mb)

94 7B 8F ;add-yt(SD-RAM 64Mb)

I assume 0x94 is SDP IO Slave Address. Is it correct? I see that 0x60 and 0x6F are defined in the SW User Guide, but I do not see any definition for 0x74, 0x75, 0x79, 0x7A, or 0x7B in the SW User Guide.

I do see in the ADV7842_Recommended_Settings_Rev1.8_17th_November_2010.pdf the following settings:

94 7A A5 // SDRAM Timing Adjustment (this is in ADV7842-VER.5.9c.txt)

94 7B 8F // SDRAM Timing Adjustment (this is in ADV7842-VER.5.9c.txt)

and the following settings for SDR SDRAM is used (not applicable to EVAL-ADV7842-7511 because it uses DDR memory):

94 74 00 // Reserved in SDR SDRAM mode

94 75 E6 // Set 64Mbit memory size and Exit Refresh Time for SDR SDRAM memory

94 79 33 // Sets CAS latency to 3

94 6F 01 // Select SDR external memory

Please note that you will need to initialize and reset the memory controller before enabling any features that use the external memory.

So you should make sure that the following write comes after your writes to these registers:

94 60 01 ; SDRAM reset

I hope this helps!

-Matt

Hi Matt,

This is not good news.  I'm sorry.

I couldn't see any improvement at both My system(64Mb SDRAM) and EVAL-ADV7842-7511 with your adviced setting.

Could you please try 3D_Comb(TBC is stopped) at EVAL-ADV7842-7511 with 64Mb SDRAM setting?

You may be able to see same issue.

I would like to make sure about 3D_Comb.

Please choose one from bellows.  

Which is coorect?

#1, 3D_Comb doesn't work with 64Mb SDRAM.

#2, 3D_Comb works with 64Mb SDRAM.  but 3D_Comb Performance quality is not good with 64Mb SDRAM comparing DDR operation.   

#3, 3D_Comb works fine with 64Mb SDRAM.   There is no difference performance between 64Mb SDRAM operation and DDR operation.

I am suspecting ADV7842 have issue at 3D_Comb(TBC is sttoped) with 64Mb SDRAM.

Regards,

Bogey

Hi Bogey,

What is the exact part number that you are using on your PCB?

Also, please send me your complete configuration script.

-Matt

Hi Matt,

Here is ADV7842 marking information which I am useing on PCB.

*******************

AD7842

KBCZ-5P

#1030 NSV

1917846.1

SINNGAPORE

*********************

Revision register is

EA : 0x20h

EB : 0x12h

I will send register setting information soon.

Regards,

Bogey

Hi Matt,

Attached file is Register setting information.

If you need any other information, please let me know.

Thank you for your support.

Regards,

Bogey

Hi Bogey,

I should clarify my question: What is the exact part number for the ADV7842 SDRAM memory device that you are using on your PCB?

-Matt