Why Your STM32N657 Can't Use SDR SDRAM (And How to Pick the Right DDR3)
I just spent some time debugging a fundamental compatibility issue between an MPU and its RAM, and I wanted to share what I learned to save others the same headache.
I was looking at using the STM32N657 (a powerful Cortex-A7 MPU) and almost made a critical error by assuming it could work with a common SDR SDRAM chip like the W9825G6KH-6.
Spoiler Alert: It can't. Here's why.
The STM32N657 has a DDR3/LPDDR2/LPDDR3 memory controller. The W9825G6KH-6 is an SDR SDRAM. These are two completely different, incompatible memory technologies.
Think of it like trying to put diesel fuel in a gasoline engine. Both are fuels, but the underlying technology and "communication protocol" are entirely different.
Post edited by ST moderator to update the wrong product name "STM32MP657" to "STM32N657".