Texas Instruments has marked the LM3S1R21-IBZ80-C5T as Obsolete. No stock-holding claim — sourced per inquiry.
The LM3S1R21-IBZ80-C5T runs an ARM Cortex-M3 core at 80 MHz — the 32-bit single-core pipeline delivers roughly 1.25 DMIPS/MHz, so the throughput ceiling sits around 100 DMIPS before flash wait-states cut in. The 256 KB on-chip flash (256K x 8) and 48 KB SRAM (48K x 8) leave room for a moderate application stack plus a real-time OS and protocol buffers. For a control-loop or protocol-stack task, the 80 MHz clock keeps the interrupt latency under 12 cycles from vector fetch to handler entry.
Industrial temperature grade and peripheral set
Rated for -40 to 85 °C ambient (TA), the device suits factory-floor controllers, outdoor telecom nodes, and engine-bay-adjacent enclosures where the ambient stays below the 85 °C ceiling. On-chip peripherals include brown-out detect, POR, PWM, WDT, and DMA; the connectivity block covers EBI/EMI, I²C, IrDA, LIN, Microwire, SPI, SSI, and UART/USART — enough to bridge to most fieldbus transceivers and serial sensors without glue logic.
108-BGA package — board integration and rework
Rework requires a hot-air station with a preheat plate; the BGA sits on the board without an exposed thermal pad, so the decoupling cap placement under the BGA shadow matters more than the pad thermal relief. The 67 general-purpose I/O break out to the outer rows and inner balls — a 4-layer board with via-in-pad or dog-bone fan-out is the practical minimum for routing.