It comes in a 100-pin TQFP package (14x14 mm) and offers 69 general-purpose I/O lines, an 8-channel 10-bit ADC, and serial interfaces including SPI, UART/USART, and USI.
Memory sizing and the firmware budget
With 32 KB of Flash (organized as 16K x 16) and 2 KB SRAM, this part fits control firmware with moderate data tables — think motor control loops, sensor fusion, or a simple HMI with a character LCD. The 1 KB EEPROM stores calibration constants and configuration parameters that survive power cycles. If your firmware image exceeds 32 KB or you need more than 2 KB of runtime RAM, you step up to the ATmega1280 or ATmega2560 family members.
I/O count and peripheral mix for system integration
69 I/O lines in a 100-TQFP give you room to connect parallel displays, keypad matrices, or multiple sensor banks without external I/O expanders. The peripheral set includes brown-out detection, power-on reset, PWM channels, and a watchdog timer — enough on-chip supervision to keep a motor drive or industrial controller running reliably without a separate supervisor IC.
It is ROHS3 compliant.