ATSAM4E8 Arm-based Flash Microcontroller Microchip Technology ATSAM4E8 Arm-based Flash Microcontroller (MCU) is based on the high-performance 32-bit Arm® Cortex®-M4 RISC processor and includes a Floating Point Unit (FPU). The ATSAM4E8 MCU delivers a maximum speed of 120MHz and features up to 1024 Kbytes of Flash, 2 Kbytes of cache memory, and up to 128 Kbytes of SRAM.