I am working with the STM32L486 and we aim to use as low clock speed as possible to conserve power. As a result, I need to improve the run time inside one high rate interrupt to meet the timing requirement. I was trying to place the routine in RAM using ramfunc but it didn't help much. I used to work with TI DSPs and this usually helped considerably. Any ideas why? Or general comments on how to speed things up, aside from running from RAM and turning on code optimization?