25 MHz Cortex-M3 with Ethernet — what the specs mean for a BOM line
The 30 I/O lines and internal oscillator keep the external BOM lean for control and communication nodes.
Ethernet on a 25 MHz core — where it fits
The Ethernet MAC is the standout peripheral here. At 25 MHz the Cortex-M3 has enough headroom to run a lightweight TCP/IP stack (like lwIP) while handling sensor polling or relay control.
The LM3S6100-EQC25-A2T is officially obsolete. For new designs, look at current Stellaris or Tiva C Series devices with Ethernet — but those will differ in supply voltage, package, and register map.