How can I add external RAM for a Cortex M7 controller? Is it even possible and if not is their any other ARM controllers where I could add more RAM to it? By RAM I mean like place to store code and libraries. I plan on having multiple sensors plugged into it, and have it show to an external screen. So I just want to be safe and be able to add more RAM if ever needed. Sorry if it's a stupid question, I am super duper new to this whole ARM world. I would just like to build a device which reads data from some sensors using i2c and then show it on a custom GUI (which would need to be rendered on the ARM Cortex). So having more RAM than not enough RAM would be ideal.
Even if this means I'd have to add some other board to allow memory expansion I would be open to it. Thank you very much all.
I suggest to ask this in the respective forum. If it is an ST chip => ST, if it is an NXP chip => NXP. If it is a self-made chip, then I have no idea where to ask. Maybe in the SoC Design forum.
I've done it with a STM32F7 / Cortex M7 mcu. Added 512k SRAM.
There is some info here: https://supersinfulsilicon.orgfree.com/stm32.html
And here's a link to the pcb: https://oshpark.com/shared_projects/gEXoyx3e
It was a lot of fun, SRAM is extremely fast. I was also surprised how fast the FRAM was on SPI.
Memory-mapped FRAM was able to stream tiny voxels for the SR71 blackbird in my demo no problem. SRAM was used for
additional backbuffers, etc. It was a lot of jumper wiring still though from the SRAM pcb to the memoryboard with FRAM and backup capacitance that was sandwiched with the STM32 Nucleo board. If memory serves me correctly, the SRAM was running at CPU / 2 so 260Mhz / 2 = ~130Mhz, one 8bit 512K/4Mbit chip. The FRAM was running at 40MHz, serial peripheral interface.
If you really want to overkill it, pair 4 of these chips for a 32bit SRAM bus. It will be a lot of wiring, or trace routing.
I've done it with a STF7 / Cortex M7 mcu. Added 512k SRAM.