80 MHz Cortex-M3 with 256 KB flash — the parametric ceiling
The LM3S5951-IQC80-C3 is a Texas Instruments Stellaris® ARM® Cortex®-M3S 5000 series microcontroller, 32-bit single-core, clocked at 80 MHz. The 256 KB on-chip flash and 64 KB SRAM define the application memory budget — the flash holds the firmware image and constant data, while the SRAM serves stack, heap, and DMA buffers.
Peripheral set and connectivity — CAN, USB OTG, and 16-channel ADC
The connectivity block includes CANbus, USB OTG, UART/USART, I²C, SPI, SSI, IrDA, LINbus, and Microwire — enough serial interfaces to bridge a sensor array, a motor drive, and a fieldbus gateway on one chip. The 16-channel 10-bit ADC samples analog inputs without an external multiplexer; the internal oscillator eliminates the crystal for non-critical timing. 67 general-purpose I/O lines in a 100-LQFP package (14×14 mm body) leave room for a parallel LCD bus or a bank of opto-coupled inputs while still routing the serial peripherals. Brown-out detect, POR, and a watchdog timer cover the basic supervisory functions — no external reset supervisor IC needed for most designs.
Texas Instruments has classified the LM3S5951-IQC80-C3 as Obsolete. A board spin is required for any pin-compatible replacement — no drop-in alternative is documented.