There are quite a few microcontroller companies out there offering Cortex M4 based MCUs.
Have you designed with the M4, and if so how do you find its usability in real-time embedded systems?
Hi Jim,
You might want to expand on "real-time" in your question as the Cortex-Rx family is actually a much better fit, as it's much more deterministic then the Cortex-Mx family...
http://www.arm.com/products/processors/cortex-r/index.php
Regards,