Re: imx6 silent memory corruption

[Nikolay Dimitrov <picmaster@mail.bg>]

Hi Eric,

On 01/28/2015 12:59 AM, Eric Bénard wrote:
> Hi Nikolay,
>
> Le Wed, 28 Jan 2015 00:35:30 +0200,
> Nikolay Dimitrov <picmaster@mail.bg> a écrit :
>> On 01/27/2015 10:51 PM, Eric Bénard wrote:
>>> Hi Nikolay,
>>>
>>> Le Tue, 27 Jan 2015 22:23:15 +0200,
>>> Nikolay Dimitrov <picmaster@mail.bg> a écrit :
>>>> On 01/27/2015 07:40 PM, Gonzalez, Alex wrote:
>>>>> Nikolay,
>>>>>
>>>>> Assuming this is a custom board, if you are using different memory or with a different configuration from the reference designs, you may need to change the memory calibration to suit the hardware. Freescale support can provide an application note that explains how to perform the calibration over a representative sample of boards.
>>>>
>>>> Yes, this is a custom board. I've already did the DDR3 calibration for
>>>> this design and validated it with 48h testing with the Freescale DDR
>>>> stress test tool (available on the IMX Community site).
>>>>
>>> are you sure of the stability of your power supplies under loard (not
>>> only the memories' one) ?
>>
>> Hmm, very good question. I haven't attached a scope to the voltage
>> rails, but that can be done easily. What would you advice for
>> considering as an acceptable voltage noise amplitude on the CPU rails?
>>
> as small as possible and no spikes under load with probe as close as
> possible to the CPU and good GND reference.

Thanks for the remark. It turned out that the board indeed had high 
power supply noise, which was causing this instability.

Regards,
Nikolay