topic Missing DRAM lines in i.MX Processors

Missing DRAM lines

olegpereverzev — Sun, 11 Jan 2015 15:12:33 GMT

Hello. In my application I am trying to couple i.MX6 with standard 240-pin DDR3 UDIMM. I've noticed that DDR3 UDIMM specifications imply that you have DQM8 and SDQS8 (and inverted /SDQS8), but there are no such pins on i.MX6. As i understand this can lead to misclocking some chips on DIMM memory device.

Is there any way to fix such trouble? Like duplicating other signal or faking it? Or any other way?

Re: Missing DRAM lines

igorpadykov — Mon, 12 Jan 2015 00:36:29 GMT

He Oleg

seems it can not be used with i.MX6, in general you can

look at datasheet and try to understand purpose of DQM8 and SDQS8.

I doubt if it can be "duplicated" or "fixed" by some way.

Best regards

igor

Re: Missing DRAM lines

Yuri — Mon, 12 Jan 2015 03:22:45 GMT

The 9-th [DQM8 and SDQS8 (and inverted /SDQS8)] is used for checking.
The i.MX6 memory controller does not support it.

~Yuri.

Re: Missing DRAM lines

olegpereverzev — Mon, 12 Jan 2015 07:47:02 GMT

Thanks. So if I will use non-ECC memory I can ignore those pins?

Re: Missing DRAM lines

igorpadykov — Mon, 12 Jan 2015 07:54:27 GMT

Probably yes.

Re: Missing DRAM lines

olegpereverzev — Mon, 12 Jan 2015 08:08:19 GMT

Thanks, I'll give it a try.