The ATmegaS64M1 is the radiation tolerant version of the popular Microchip ATmega64M1 8-bit AVR microcontroller. This high-performance, low-power Microchip 8-bit AVR RISC-based microcontroller combines 64KB ISP flash memory with read-while-write capabilities, 2KB EEPROM, 4KB SRAM, 27 general purpose I/O lines, 32 general purpose working registers, one motor power stage controller, two flexible timer/counters with compare modes and PWM, one UART with HW LIN, an 11-channel 10-bit A/D converter with two differential programmable gain input stages, a 10-bit D/A converter, a programmable watchdog timer with internal individual oscillator, SPI serial port, an on-chip debug system, and four software selectable power saving modes. By executing powerful instructions in a single clock cycle, the device achieves throughputs approaching 1 MIPS per MHz, balancing power consumption and processing speed. With its CAN controller, power stage controller, ADC, DAC and analog comparators the ATmegaS64M1 microcontroller is a great choice for many of the most common space applications, which typically require a small footprint and low power. The device operates between 3-3.6 volts. This space-qualified version of the product adds: Ceramic & Hermetic packages, extended temperature range -55C to 125C, extended qualification flow equivalent to QML-V or QML-Q space grade. Radiation performance for the ATmegaS64M1: SEL LET > 60 MeV.cm2/mg (at 125C), and TID up to 30 Krad (Si).