The LM3S9997-IQC80-C0T is a Stellaris ARM Cortex-M3S 9000 series 32-bit single-core microcontroller clocked at 80 MHz. It has 256 KB Flash, 64K x 8 RAM, and a 16-channel 10-bit ADC.
80 MHz Cortex-M3 — what it buys you on the bus
The 80 MHz core speed positions this MCU in the mid-performance tier of the Cortex-M3 family. It gives you enough headroom to run a lightweight TCP/IP stack alongside a CANopen or Modbus master task without stalling the control loop. The internal oscillator means you can skip an external crystal for non-critical timing, saving two pins and a couple of passives.
256 KB Flash + 64 KB RAM — firmware and data budget
256 KB of Flash is enough for a bootloader, a real-time OS kernel, and a moderate application image with Ethernet and CAN stacks. The 64 KB SRAM handles packet buffers and task stacks without external memory.
Obsolete — sourcing reality for the BOM line
Texas Instruments has marked the LM3S9997-IQC80-C0T as obsolete. The last-time-buy window has closed. For sustaining production, the only supply channel is the independent surplus and broker market.
Package and mounting — 100-LQFP 14x14 mm
The 100-LQFP package measures 14x14 mm. The 60 GPIOs are distributed on all four sides.