The ATTINY25-20SSU is a 8-bit low-power AVR RISC-based Microcontroller Unit combines 2kB ISP flash memory, 128B EEPROM, 128B SRAM, 6 general purpose I/O lines, 32 general purpose working registers, one 8-bit timer/counter with compare modes, one 8-bit high speed timer/counter, USI, internal and external Interrupts, 4-channel 10-bit A/D converter, programmable watchdog timer with internal oscillator, three software selectable power saving modes and debug wire for on-chip debugging. The device achieves a throughput of 20MIPS at 20MHz and operates between 2.7 to 5.5V. By executing powerful instructions in a single clock cycle, the device achieves throughputs approaching 1MIPS per MHz, balancing power consumption and processing speed.