80 MHz Cortex-M3 — enough headroom for a mixed workload
80 MHz on a Cortex-M3 is a comfortable spot for an industrial gateway that handles protocol bridging without needing a separate communications co-processor. The Ethernet MAC runs the TCP/IP stack; the CAN controllers handle the drive bus; the USB OTG can serve a configuration port or a data-logging stick. The 48 KB RAM is tight for heavy buffering — plan your packet queues accordingly.
Texas Instruments has marked the LM3S9L97-IQC80-C3T as Obsolete. No last-time-buy window remains through the factory channel. If you are qualifying a new design, look for a pin-compatible or functionally equivalent current-production Stellaris or Tiva C Series device; the LM3S9L97 sits in the 100-LQFP footprint, and TI's Tiva TM4C129x family is a common migration target for Ethernet+CAN applications.