256 KB Flash, 16 KB RAM, 4 KB EEPROM — memory map for a standalone node
The Microchip ATXMEGA256C3-AU is an 8/16-bit AVR XMEGA C3-series microcontroller in a 64-TQFP package, built around a 32 MHz AVR core. Fifty general-purpose I/O lines, a 12-bit 16-channel ADC, and a full-speed USB 2.0 peripheral with dedicated DMA channels make it a single-chip fit for data-acquisition and human-interface products. Brown-out detection, power-on reset, and a watchdog timer are integrated, so the BOM can skip external supervisor ICs in most industrial and consumer designs.
USB plus serial — what the connectivity block drives
The USB peripheral with dedicated DMA can sustain HID and CDC virtual-comport data rates without CPU overhead. Alongside USB, the part provides I2C, SPI, and multiple UART/USART channels, plus IrDA support — enough to bridge a legacy RS-232 sensor to a modern USB host in a single chip. The 12-bit ADC with 16 multiplexed channels captures analog sensor inputs directly.