Based on ARM’s powerful Cortex-M4 core, Microchip's SAM4S series offers increased performance and power efficiency, higher memory densities, up to 2MB of Flash and 160KB of SRAM, along with an extensive peripheral set for connectivity such as Full Speed USB Device and SD card interface, a CMOS interface, system control and analog interfacing. The SAM4S operates at 120MHz and integrates Microchip's Flash read accelerator, along with optional cache memory to increase system performance. It also features a multi-layer bus matrix, multi-channel direct memory access and distributed memory to support high data rate communication. The SAM4S series manages to achieve 180 µA/MHz in dynamic mode, 25 µA in RAM retention mode, and 1 µA at 1.8V in back-up mode with the real-time clock running. On the security side, the SAM4S prevents unauthorized access to on-chip memory and supports secure device reconditioning for reprogramming, while a 128-bit ID and scrambled external bus interface ensures software confidentiality as the hardware cyclic redundancy check checks memory integrity. To accelerate development with the SAM4S Cortex-M4 MCU, Microchip offers several SAM4S evaluation kits which allow engineers to more easily evaluate the device.