Troubleshooting DDR memory

VICTOR LEITE

Other Parts Discussed in Thread: AM3359

Hi everybody,

I've been working on a beaglebone clone board which is not executing OS, app or any code supposed to be located from 0x80000000 onwards.

I've saw a post at google groups where an user says:

"If you do not clone it EXACTLY, PCB layout. then you have to run special SW using Code Compose Studio to calculate the DDR timings. They are different if you change the routing on the DDR."

If this information is right, could somebody point me to this "special software" in order to "calculate" DDR timings? Although it's a clone, perhaps little diferences in pcb routing or manufacturing could be causing the problem.

Furthermore, is there any way to check if memory is working at least?

I'm using CCS 5.5.0, XDS100v2 (FT2232H), and AM335X_StarterWare_02_00_01_01.

Bootloader, *.ccxml and GEL files are ok since I can run them on a original beaglebone.

Thanks,

Victor Leite

over 11 years ago

0 Biser Gatchev-XID over 11 years ago

TI__Guru**** 393215 points

Hi Victor,

I can't say about Starterware, but here is a tutorial that describes the DDR3 tuning process in detail: http://processors.wiki.ti.com/index.php/Sitara_Linux_Training:_Tuning_the_DDR3_Timings_on_BeagleBoneBlack.

0 VICTOR LEITE over 11 years ago in reply to Biser Gatchev-XID

Intellectual 550 points

Hi Biser,

I'm working with the early beaglebone which has a DDR2 external memory. I can't find any similar documentation for it. Do you know if it exists? Let me know if so, please.

Thank you

0 Biser Gatchev-XID over 11 years ago in reply to VICTOR LEITE

TI__Guru**** 393215 points

Hi Victor,

I hadn't realised that. For DDR2 tuning there is only the procedure described here: http://processors.wiki.ti.com/index.php/AM335x_EMIF_Configuration_tips. Just follow the steps described for DDR2.

0 VICTOR LEITE over 11 years ago in reply to Biser Gatchev-XID

Intellectual 550 points

Biser,

I've found a spreadsheet for DDR2 (AM335x DDR2 Timing Configuration Tool)

I've checked timings but the DDR_DataTransferCheck script still fails.

I'm trying to probe the DDR clock output from the AM3359. I'm not sure what I'm doing wrong but I couldn't get this signal. Do you have experience with that kind of probing?

Thanks

0 Biser Gatchev-XID over 11 years ago in reply to VICTOR LEITE

TI__Guru**** 393215 points

This is a signal in the 125 - 266MHz range. Your scope should be better than 500MHz and you should use high quality low-capacitance probes to check this.

0 VICTOR LEITE over 11 years ago in reply to Biser Gatchev-XID

Intellectual 550 points

Biser

The ddr_ck from processor can't be seen at the trace it was supposed to be.
That was confirmed by a measuring today (It was compared with an original board with the same steps)

I'm gonna send a few boards to a X-ray inspection in order to know if there is something wrong with assembling and which pads are not properly connected.

Thanks

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Troubleshooting DDR memory