External input voltage when using MR25H00-EVAL with NUCLEO-F411RE board

Over the past couple of days, I have been able to successfully run the MRAM_MR25H00-EVAL demonstration code in Keil Studio using the MR25H00-EVAL SPI (that hosts Everspin’s 4Mb MR25H40 MRAM) and the MCU board NUCLEO-F411RE.

Now, I would like to potentially use external inputs by connecting a source to the SI pin of the MR25H00-EVAL to WRITE information onto the MRAM device, rather than just the standard “Reset button” and “Press any key on your keyboard” inputs as suggested by the instruction manual. Since the voltage operating range of the MR25H40 MRAM chip is 3.0-3.6V, I want to know if supplying additional power to the SI pin on the SPI shield will damage my MRAM chip as it is already drawing power to run from the NUCLEO-F411RE board, which is connected to my PC via USB.

This is technically still a hypothetical question because I still need to finish my code, which will use the MRAM_MR25H00-EVAL demonstration program as a reference, in order to READ the desired external inputs. However, I would love to hear your thoughts on this matter. Any other suggestions about ways to improve what I have described above are also welcome with open arms. Since I am still in the early development stages of this “project”, any help is invaluable.


P/s: Here is the link to the MRAM_MR25H00-EVAL demonstration code. Additionally, you can get the instruction manual for the MR25H00-EVAL SPI here, that for the MR25H40 MRAM chip here, and that for the NUCLEO-F411RE here.


to be honest I am not sure what you exactly mean with

SI (MOSI) pin is one of four SPI pins what are dedicated for serial communication with its master, in this case your Nucleo board. So I do not understand your idea about external voltage to this pin.

BR, Jan