Core and memory headroom for control applications
The LM3S1B21-IQC80-C5T: On-chip memory pairs 256 KB of flash with 96 KB of SRAM — enough to run a real-time control loop with a moderate data buffer without external memory. The 80 MHz core delivers roughly 1.25 DMIPS/MHz, so the effective throughput is about 100 DMIPS — sufficient for motor control, industrial protocol bridging, or human-machine interface processing.
67 general-purpose I/O pins are available, along with an external bus interface (EBI/EMI) that can connect to parallel LCDs, FPGAs, or external memory. Serial connectivity covers I²C, SPI, SSI, UART/USART, LIN, IrDA, and Microwire — enough to talk to sensors, displays, and fieldbus transceivers on one chip. An 8-channel 10-bit ADC is integrated for analog signal acquisition. On-chip peripherals include a PWM generator, watchdog timer, DMA controller, and brown-out reset — the usual set for a standalone control MCU without external supervisor ICs.
Texas Instruments has marked the LM3S1B21-IQC80-C5T as obsolete. For existing designs that cannot spin a board, sourcing through independent distribution is the only path. A BOM review to identify a functional replacement in a different package or pinout may be the longer-term solution.