STM32MP157 Memory

[TechSys]

Hi,

I am designing a product based on the STM32MP157DAC specifically using the TFBGA257 package due to its compact size. I was just looking at the datasheet (page 16, Table 1) and noticed that under the SDRAM section it seems that this package doesn't support 32 bit. I have trawled the internet for additional information to support this but can't find anything that might suggest this to be the case. Can anyone chime in if you've had any experience using this package or if you know of any additional literature.

Cheers,

[Erwan SZYMANSKI]

Hello @TechSys ,
As you mention it regarding the datasheet of your package, there is no support of 32-bit DDR3 for the TFBGA257 or LFBGA354 package.

You can also see in the DDR memory routing guidelines Application Note that this configuration is not supported.

Kind regards,
Erwan.

[PatrickF]

HI @TechSys 

Notice that STM32MP157DAC is TFBGA361 12x12mm (which support 16-bits and 32-bits DDR) whereas STM32MP157DAD is TFBGA257 10x10mm (which support 16-bits DDR only)

Anyway, you could start your design by looking at:

• system wise, the STM32MP157F-DK2 board which use TFBGA361 with a single 16-bits DDR3L (so you could use similar for TFBGA257)
• more specifically for DDR3L routing, the STM32MP15x Series DDR memory routing guidelines examples where you could find a recommended layout for TFBGA257 with 16-bits DDR3L (folder named STM32MP15XXAD_1DDR3L)

Regards.