how to use DDR3L with STM32mp257Fak3

[abhineetranjan]

Hello 
I am planning to use STM32mp257Fak3 with DDR3L (16bit and 32 bit saperately),
can you suggest some DDR part no and it's sonnection.

[Pwxn]

Hello @abhineetranjan 

You can refer to this 2 application notes:

https://www.st.com/resource/en/application_note/an5723-guidelines-for-ddr-configuration-on-stm32mp2-mpus-stmicroelectronics.pdf

https://www.st.com/resource/en/application_note/an5724-guidelines-for-ddr-memory-routing-on-stm32mp2-mpus-stmicroelectronics.pdf

ST follow the JEDEC standards so you should be able to choose any part that are following the same.

"DDR3L with a data rate of 2133 MT/s, voltage at 1.35 V. More information on DDR3L SDRAM can be found
on the JEDEC DDR3 SDRAM Standard JESD79-3F." - AN5724 2 Design interface constraints

I hope this will help you.

Regards,

[abhineetranjan]

Thank you for your response,
can I use 2 , 8bit DDR3L with STM32MP257FAL3 (as this is not mentioned in the pdf you provided), to achieve 1GByte Memory density.

Best Regards
Abhineet Ranjan

[abhineetranjan]

Block Diagram for reference....

[abhineetranjan]

Hello,
I am using 16 bit DDR3L (MT41K512M16VRP-107) with STM32mp257FAK3, 
the available Nets in processor is 32 (32-bit), what should be done with the remaining Databus (should it be terminated or left floating or pull down.

Best regards,
Abhineet Ranjan

[PatrickF]

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@abhineetranjan wrote:

Hello,
I am using 16 bit DDR3L (MT41K512M16VRP-107) with STM32mp257FAK3, 
the available Nets in processor is 32 (32-bit), what should be done with the remaining Databus (should it be terminated or left floating or pull down.

Best regards,
Abhineet Ranjan

---

Leave them open. Note that you should connect you 16-bit memory on DQ0-15.

AN5489 could help (even if DDR3 is not listed in it).
You could also have a look to provided DDR3L routing example in STM32MP2 Series DDR memory routing guidelines examples  (altough does not cover 16-bit DDR on 32-bit interface).

Regards.