Showing results for 
Search instead for 
Did you mean: 


Senior III

Using STM32H743IGKx.

Tools: Linux


Version: 1.12.1
Build: 16088_20230420_1057 (UTC)


Version: 6.8.1-RC4
Build: 20230419-1431 (UTC)

When setting up the SDRAM configuration in MX, I end up with a couple of signals that look like they are not needed so this post is serving as a sanity check.  The signals are FMC_NL and FMC_SDNWAIT.  I am interfacing to a MT48LC16M16A2 – 4 Meg x 16 x 4 banks.  There are no connections for the NL and WAIT signals.  As far as I can tell the NL line is unnecessary as the address lines and data lines are not muxed back to the MCU and cube MX shows that in the FMC Configuration, GPIO Settings tab since all the signals for address and data have unique pin assignments.  So can I safely ignore this signal?  Secondarily, and less important, why would Cube MX include this signal and assign a pin when there is no mux-ing occurring?  It does not so it when setting up a design using the STM32H743I-EVAL and the signal is also not on the reference design.

As for the WAIT signal, since there is no where to place this signal on the SDRAM.  Referring to the STM32H743I-Eval schematic, this line is only used for the Nor Flash and rightfully has a place to go there, but it also is not used in conjunction with the SDRAM.  So the same two questions?

This makes me wonder if there is some attention that needs to be paid to the next version of CubeMX to not instantiate these signals where that don't apply and leave the connections for something else that the user might need.  In my case, I am not at all IO constrained so no big deal if I ignore them if that is the right thing to do.

Hopefully there is someone with expertise in this area who can chime in.

Best Regards to the community.