My customer Cruise is starting an new S32g3 design and they want to use slower speed grade
The S32G399 Reference board has a -053 speed grade LPDDR4 part. But they are planning to use a -46 speed grade part.
What needs to change in order to boot linux from this slower LPDDR4?
Or is it mandatory to use a -053 speed grade?
You seem to mix up speed grades, -046 is a faster memory than -053. In that sense -046 is ok of course.
On the other hand the S32G3 supports DDR4LP at up to 3200MT/s speed, both speed grade parts meet this speed. No change in sw setup is required.