80 MHz Cortex-M3 with Ethernet and USB OTG
The Texas Instruments LM3S9B96-IQC80-C3 is a Stellaris ARM Cortex-M3S 9000 series microcontroller running at 80 MHz with a 32-bit single-core processor. It packs 256 KB of Flash for program storage and 96 KB of SRAM for data — enough headroom for a full TCP/IP stack with a real-time control loop. The connectivity set includes Ethernet MAC+PHY, USB OTG (Host/Device), two CAN 2.0B controllers, plus UART, I²C, SPI, SSI, and IrDA — making it a single-chip control node for industrial gateways, building automation controllers, and networked motor drives.
Memory map and peripheral allocation
256 KB of on-chip Flash (256K x 8) and 96 KB of SRAM (96K x 8) give the application layer room for a real-time OS, Ethernet buffer pools, and a control algorithm without external memory. The EBI/EMI interface expands memory off-chip when needed. The 65 general-purpose I/O pins are multiplexed with the full peripheral set: two I²S audio interfaces, quadrature encoder inputs (QEI), PWM channels, and a 16-channel 10-bit ADC. The DMA controller offloads data movement from the CPU for high-throughput Ethernet or USB transfers. The internal oscillator eliminates an external crystal for the core clock, though the Ethernet PHY still needs a 25 MHz reference.
Surface-mount assembly with MSL 3 handling is typical for this package class — a 24-hour bake before reflow if the moisture barrier bag is compromised. The 0.5 mm pitch demands a solder paste stencil aperture of about 0.25 mm width for reliable fillet formation.
Texas Instruments has marked the LM3S9B96-IQC80-C3 as obsolete. No official successor part number is published in the Stellaris family for a direct drop-in replacement — the Stellaris line has been superseded by the Tiva C series, but those parts use a different pinout and peripheral map. Stock is lot-specific with date codes varying; each quote confirms the available date-code range and quantity.