topic Re: Hardware design IMX8QM and DDR4 in i.MX Processors

Hardware design IMX8QM and DDR4

timur_kh — Fri, 01 Jan 2021 17:29:55 GMT

Hello everyone!

I am designing a mini PC on an IMX8QM processor.
I need help choosing and connecting DDR4 SDRAM.
I want to use SDRAM MT40A series from Micron manufacturer. But I cannot choose between MT40A512M8 and MT40A256M16.
The document "i.MX8 QM / i.MX8 QXP Hardware Developer's Guide" provides examples for DDR3L and LPDDR4 only.
DDR design is not yet available in Config Tools for i.MX Version 8.0.
The most productive document is the schematic "MCIMX8QM-CPU MEK Platform", page 14 shows connection to LPDDR4 - MT53E768M32, indicating the pins for DDR4. I started making a circuit with MT40A256M16, then with MT40A512M8, but every time I missed some pins, for example ODT1 or DMI0_A.
Then in the schematic I read "The processor requires x16 for each chip inside the DRAM package. The x8 configuration is not compatible."
Does this note mean that I cannot use MT40A512M8? But why then is MT53E768M32 used in the example? After all, if I understand correctly there requires x32.
Please tell me which DDR4 SDRAM to choose (you can buy from 1 unit, not 2000 units) and examples of connection and settings.

Re: Hardware design IMX8QM and DDR4

igorpadykov — Sat, 02 Jan 2021 00:58:57 GMT

Hi timur_kh

i.MX8QM does not support DDR4 as described in datasheet, for example Table 1, 4

i.MX 8QuadMax Automotive and Infotainment Applications Processors

Best regards
igor

Re: Hardware design IMX8QM and DDR4

timur_kh — Sat, 02 Jan 2021 04:13:50 GMT

Hi igorpadykov!

The comparison table states that the i.MX8QM supports LPDDR4 and DDR4. The i.MX8QM schematic also contains DDR4.Hence there is hope for DDR4 support!)

Or the comparison table contains a typo

https://www.nxp.com/products/processors-and-microcontrollers/arm-processors/i-mx-applications-processors/i-mx-8-processors:IMX8-SERIES

Re: Hardware design IMX8QM and DDR4

igorpadykov — Sun, 03 Jan 2021 10:37:13 GMT

correct comparison table :

https://www.nxp.com/docs/en/supporting-information/IMX8LAYERCMPR.pdf

Best regards
igor

Re: Hardware design IMX8QM and DDR4

timur_kh — Thu, 07 Jan 2021 05:54:29 GMT

Thank you!