RTOS/TMS320C6657: TMS320C6657 - MT41K512M8 Possible DDR3 Timing Issues

Eric Woodward

Part Number: TMS320C6657

Tool/software: TI-RTOS

Hello,

I have plugged in values from the Micron MT41K512M8 datasheet into DDR3 Register Calc v4 spreadsheet, but since my part wasn't listed I did the best I could to add the necessary values.

I've been chasing some odd memory behavior in two flavors. One is failed readback values in a simple walking 1's type ram test. The second issue I've noticed is hitting breakpoints for a second time in my main startup thread after it has already executed, and I can't tell if it's a second instance or if somehow the PC has jumped.

With both cases, I figured it would be best to start by asking for a verification of my EMIF configuration registers for a 1066 Data Rate.

DDR_SDTIM1	0x21000018	0CCF36B3
DDR_SDTIM2	0x21000020	308F7FDA
DDR_SDTIM3	0x21000028	557F88AF
DDR_SDCFG	0x21000008	63026B33
DDR_SDRFC (normal)	0x21000010	00001046
DDR_SDRFC (ext temp)	0x21000010	00000823
DDR_SDRFC (initialization)	0x21000010	0000411A

Happy new year,

Eric

over 6 years ago

0 Yordan Kovachev over 6 years ago

TI__Guru**** 161600 points

Hi,

On first glance, the register values seem ok.
When designing your board, did you follow the DDR3 Design Requirements Document:
www.ti.com/.../sprabi1c.pdf

Then also the DDR3 Initialization app note (combined with the use of the DDR3 Register Calc v4 spreadsheet) would be useful: www.ti.com/.../sprabl2e.pdf

Are you able to get your DDR initialized with the GEL file?

Best Regards,
Yordan

0 Eric Woodward over 6 years ago in reply to Yordan Kovachev

Prodigy 90 points

Yordan, thank you.

I followed the design requirements, and also the the app notes. I largely reused/modified the DDR3 initialization code from the 6657 eval module according the the app notes.

Also, the phy calc spreadsheet values were generated according to the actual trace length values.

I've been suspecting a clock issue, if not some gross error I made in the timing and configuration values.

-Eric

0 Tom Johnson 16214 over 6 years ago in reply to Eric Woodward

TI__Mastermind 46460 points

Eric,

You mentioned that you are only running the DDR interface at 1066MT/s which implies that the DDR clock is at 533MHz. Have you verified that the clock configuration is correct?

Yordan indicated the documents that you should be referencing. The following wiki page mentions these documents too but also walks you through the critical steps for commissioning a DDR interface on the C6657:

http://processors.wiki.ti.com/index.php/KeyStone_I_DDR3_Interface_Bring-up

Please post here your completed report showing that the length matching rules have been met. Then also provide your completed PHY_CALC and REG_CALC worksheets.

Tom

0 Tom Johnson 16214 over 6 years ago in reply to Tom Johnson 16214

TI__Mastermind 46460 points

Eric,

Please post the requested information so that we can support your debug. Alternately, if you have resolved your problem, please let us know what you found.

Tom

0 Tom Johnson 16214 over 6 years ago in reply to Tom Johnson 16214

TI__Mastermind 46460 points

Eric,

We will close this thread if we do not hear from you in the next few days.

Tom

0 Tom Johnson 16214 over 6 years ago in reply to Tom Johnson 16214

TI__Mastermind 46460 points

Eric,

I am closing this thread since you have not responded. If you post to it, it will reopen unless it is locked. After that time, you will have to open a new thread.

Tom

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RTOS/TMS320C6657: TMS320C6657 - MT41K512M8 Possible DDR3 Timing Issues