80 MHz Cortex-M4 with 1 MB flash — the firmware budget
The STM32L476QGI3 runs an ARM Cortex-M4 core at 80 MHz, backed by 1 MB of on-chip flash and 128 KB of SRAM. That flash is the full 1 MB — the bootloader does not steal a sector, so the firmware image gets the entire bank. The 128 KB RAM splits across the main SRAM and a dedicated 8 KB SRAM for the LCD controller if you use it, but the core 128 KB is contiguous for code and data.
Peripheral set and pinout — 109 I/O in a 7x7 mm BGA
The 132-UFBGA package measures 7x7 mm with a 0.50 mm ball pitch. That pitch demands a 4-layer PCB for fan-out — two-layer boards will not route the inner rows. The 109 I/O pins map to a rich peripheral set: USB OTG FS, two CAN interfaces, a Quad SPI for external flash, and multiple SPI/I²C/UART channels. The QSPI interface is worth calling out — it allows memory-mapped access to an external serial NOR flash at up to 80 MHz, effectively extending the code space beyond the internal 1 MB without a parallel bus. The EBI/EMI controller on the same pins can drive a parallel LCD or SRAM if needed, but the two functions share pins, so the design must choose one.
Active lifecycle — no LTB pressure for new designs
ROHS3 compliant per the manufacturer's declaration.