The Texas Instruments LM3S615-EQN50-C2T is a 32-bit ARM Cortex-M3 microcontroller from the Stellaris® 600 series, clocked at 50 MHz. It carries 32 KB of Flash program memory and 8K x 8 of SRAM, with 34 GPIOs, a 2-channel 10-bit ADC, and serial interfaces covering I²C, Microwire, SPI, SSI, and UART/USART. The part is rated for industrial environments from -40°C to 105°C and comes in a 48-LQFP (7x7) surface-mount package.
50 MHz Cortex-M3 — what it means for the control loop
The 50 MHz core speed on this Stellaris part is enough for a single motor-control PWM loop or a Modbus RTU master with a few analog inputs. It is not a high-throughput part — the 8K x 8 SRAM limits buffering for Ethernet or heavy data logging. For a simple drive controller or a sensor hub handling one or two UART streams, the 50 MHz Cortex-M3 with its integrated PWM and watchdog peripherals is a clean fit. The internal oscillator saves a crystal on the BOM, though for timing-sensitive CAN or precision PWM you will want an external clock source.