Supported PSRAM and Flash for the STM32N6xx

[RAdam.1]

Hey guys,

I'm looking for some suitable HexaSPI PSRAM and also the OctoSPI Flash for the STM32N645 board I am just building.. I cant find the parts used on the DK so do you have a list of supported memories? I need 256Mb PSRAM and will start with a 1Gb Flash as per the DK.. 

Richard

[RomainR.]

Hello @RAdam.1 

If you refer to the latest External Memory Manager Middleware,
STM32Cube_FW_N6_V1.3.0\Middlewares\ST\STM32_ExtMem_Manager\Release_Notes.html

You will find a list of NOR Flash SFDP from Winbond and Gigadevice manufacturer which are compatible with STM32N6.
Actually, concerning Hexa PSRAM/HyperRAM, only the APMemory APS256XXN-OBR-BG was validated on STM32N6.
After checking, it seems that the APS256XXN is available at Mouser.com.

APS256XXN-OBR-BG AP Memory - Distributors and Price Comparison | Octopart component search

Best regards,

Romain

[johnchargo]

It sounds like I'm in the same position as the original poster.

The recommended PSRAM APS256XXN-OBR-BG is showing as nearing the end of its lifecycle and not recommended for new designs. The manufacturer recommends APS256XXN-OB9-BG as a replacement.

Can anyone comment on the compatibility of APS256XXN-OB9-BG with the N6?

[RomainR.]

@johnchargo 

I reviewed the respective datasheets:

APS256XXN-OBRx – APM Octal PSRAM Datasheet, Rev. 1.00
APS256XXN-OBx9 – APM OPI/HPI Xccela PSRAM Datasheet, Rev. 1.2

The memory devices support the following serial interfaces with the Xcella support on OBx9 part number:
APS256XXN-OBRx: DDR Octal SPI
APS256XXN-OBx9: OPI/HPI and also supports Xccela™ mode for PSRAM

The main differences concern operating frequency and data rate:
APS256XXN-OBRx: Up to 200 MHz (400 MB/s in X8, 800 MB/s in X16)
APS256XXN-OBx9: Up to 250 MHz (500 MB/s in X8, 1000 MB/s in X16)

All other specifications listed below appear to be fully compatible:

Both part numbers are pin-to-pin compatible and share the same package dimensions.
Power-up initialization uses the same method and timing.
Address space, burst type and length, and command/address latching are identical.
The command truth table is the same.
Read operations use the same address/data transfer sequence and timing.
Write operations also appear to be aligned.

In my opinion, the APS256XXN-OBx9 should be compatible with STM32N6 XSPI without any modifications but limited to 200MHz with DQS.

Best regards.
Romain,