Here's a breakdown of its key features based on the provided information:

Architecture: 8-bit AVR RISC The microcontroller is based on the 8-bit AVR (Advanced Virtual RISC) architecture. AVR microcontrollers are known for their high performance, low power consumption, and rich peripheral features.

Flash Memory: The MCU has 64 kilobytes (KB) of on-chip Flash memory for program storage. This memory allows for storing the program code that controls the microcontroller's behavior.

Voltage Range: The MCU supports operation at both 3.3 volts (V) and 5 volts (V). This flexibility in voltage compatibility allows for use in a variety of applications with different power requirements.

Package Type: 64-Pin TQFP (Thin Quad Flat Package) The microcontroller is packaged in a 64-pin Thin Quad Flat Package (TQFP), which is a surface-mount package with leads extending from all four sides. TQFP packages offer a compact footprint and are suitable for automated assembly processes.

SMD: Surface Mount Device The microcontroller is designed for surface-mount assembly onto a printed circuit board (PCB). SMD components are soldered directly onto the surface of the PCB, rather than through holes, allowing for denser and more compact designs.