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gosal
Associate II
April 19, 2024
Solved

STM32 Muxed FMC reference schematic

Hi,

I'm working on a hardware design using the STM32F765VIH and I am trying to connect a MT28EW128ABA1HPC-0SIT NOR Flash and IS66WVH16M8DBLL-100B1LI PSRAM to the FMC in muxed mode. I'm struggling to understand how the muxed connection should be made and although I've searched a lot I cannot seem to find any reference schematics for this. 

 

Can anyone point me to reference material that could help me?

 

Thanks,

George

 

Edit: Corrected NOR Flash part number, was previously wrongly written as part IS29GL128-70DLEB

This topic has been closed for replies.
mƎALLEm
mƎALLEmBest answer
ST Technical Moderator
April 19, 2024

Hello,

MT28EW128ABA1HPC: same thing -> No muxed Address-Data busses:

SofLit_0-1713541562722.png

Unfortunately (to my knowledge) there is no reference design provided by ST as all STM32 MCU boards are using memories having separated Address/Data lines: direct connections data-data, address-address (no shared busses / neither external latches).

To give better visibility on the answered topics, please click "Best answer" on the reply which solved your issue or answered your question.

5 replies

waclawek.jan
Super User
April 19, 2024

What exactly do you mean by "muxed mode" here?

The PSRAM appears to be HyperBus interfaced; FMC does not support HyperBus. The 'F7 family does not have OCTOSPI interface which supports HyperBus, read AN5050.

JW

mƎALLEm
ST Technical Moderator
April 19, 2024

Hello,

Not sure how do you plan to connect a HyperRAM to the FMC interface! The protocol is quiet different!

SofLit_0-1713539200286.png

Regarding the NOR Flash, FMC muxed mode needs either a memory having natively a shared Address-Data lines (which is not the case of IS29GL128-70) or you need to add external latches to hold the address during the read/write operations.

To give better visibility on the answered topics, please click "Best answer" on the reply which solved your issue or answered your question.
gosal
gosalAuthor
Associate II
April 19, 2024

Sorry I had specified the wrong part number for the NOR Flash, I'm considering the MT28EW128ABA1HPC-0SIT but regardless of the actual partnumbers is there any reference design that shows how to interface the muxed FMC to standard parallel NOR Flash or PSRAM ?

mƎALLEm
mƎALLEmBest answer
ST Technical Moderator
April 19, 2024

Hello,

MT28EW128ABA1HPC: same thing -> No muxed Address-Data busses:

SofLit_0-1713541562722.png

Unfortunately (to my knowledge) there is no reference design provided by ST as all STM32 MCU boards are using memories having separated Address/Data lines: direct connections data-data, address-address (no shared busses / neither external latches).

To give better visibility on the answered topics, please click "Best answer" on the reply which solved your issue or answered your question.