LPDDR4 Memory for STM32MP257

[altsir_sga]

Hi,

I am in the middle of the project development based on STM32MP257FAK CPU. Originally we were using 8Gbit Micron chip (MT53E256M32D1) which became obsolete in the middle of the development, it even seems that most of the 8Gbit Micron chips are now obsolete. Now would like to understand why all the validated LPDDR4 memories in the wiki list are 2133MHz while the operating memory speed for STM32MP257 is 1200MHz?

Are there any know issues with this memory for example from ISSI: IS43LQ32256A-062BLI? This is 1600MHz memory.

Thanks!

Alexey.

[PatrickF · Accepted solution]

Hi @altsir_sga 

no issue to use a memory at 1200MHz with speed grade equal or above 1200MHz.

The device choice on our reference design are just driven by availability at the time the memory were tested.

The major constrain we have is that you must use a single rank LPDDR4 (i.e. single CS per channel). The IS43LQ32256A-062BLI sound ok with that constrain.

Please refer to AN5723, AN5724 and AN5489.

Regards