The SAM4S series is a member of a family of Flash microcontrollers based on the high-performance 32-bit ARM Cortex -M4 RISC processor. It operates at a maximum speed of 120 MHz and features up to 2048 Kbytes of Flash, with optional dual-bank implementation and cache memory, and up to 160 Kbytes of SRAM. The peripheral set includes a full-speed USB Device port with embedded transceiver, a high-speed MCI for SDIO/SD/MMC, an External Bus Interface featuring a Static Memory Controller to connect to SRAM, PSRAM, NOR Flash, LCD Module and NAND Flash, 2 USARTs, 2 UARTs, 2 TWIs, 3 SPIs, an I2S, as well as a PWM timer, two 3- channel general-purpose 16-bit timers (with stepper motor and quadrature decoder logic support), an RTC, a 12-bit ADC, a 12-bit DAC and an analog comparator. The SAM4S series is ready for capacitive touch, offering native support for the QTouch library for easy implementation of buttons, wheels and sliders. In Backup mode, only the low-power RTC and wakeup logic are running. The real-time event management allows peripherals to receive, react to and send events in Active and Sleep modes without processor intervention. SAM4S devices operate from 1.62V to 3.6V.