DDR Stress Tools v2.52 didn't pass low frequency during stress test

[wallyyeh]

Hi, All:

   Our new product have some memory issue which old product didn't, we did the calibration test and update the MMDC registers(uboot/board/freescale/mx6q_sabresd/flash_header.S). now it can pass DDR stress test for range 413 ~ 585MHz. (but old product can pass 413~672MHz)

   According Freescale i.MX6 DRAM Port Application Guide-DDR3 , in page 19, it says:

If the DDR3 cannot even pass the stress test at a low frequency, say 200 MHz, it is more likely to be a

hardware problem. Then, it would be a good starting point to check the DDR3 connections. In addition,

you should check the power supply for the DDR3, i.MX6 MMDC and DDR3 I/O to see if voltage is valid

and ripple is not too large.

    Our new product never success on frequency lower than 400Mhz, is this situation just fine or not?

[igorpadykov]

Hi Wally

one can check with oscilloscope power supplies ripples (should be <5%) and

ddr signals waveforms . Also one can experiment to determine if it is a

hardware PCB issue: hand solder 22uF capacitors directly under center of chip.

May be recommended to tweak with drive strength settings.

Best regards

igor

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[wallyyeh]

Dear igorpadykov:

    Thanks for reply. :smileyhappy:

so our product "should" pass the lower frequency DDR stress test, right?

I'll tell HW partner to check the advice which you give.

[igorpadykov · Accepted solution]

Hi Wally

yes it should pass lower frequency DDR stress test

Best regards

igor