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. If your application needs more than that, you are looking at a different density tier — but for a single-protocol gateway or a motor-drive controller with HMI, this is the sweet spot.
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.