The Atmel? | SMART SAM G54 is a series of Flash microcontrollers based on the high-performance 32-bit ARM? Cortex?-M4 RISC processor. They operate at a maximum speed of 96 MHz and feature up to 512 Kbytes of Flash and 96 Kbytes of SRAM. The peripheral set includes one USART， two UARTs， three I2C-bus interfaces （TWI）， up to two SPIs， two three-channel general-purpose 16-bit timers， two I2 S controllers with two-way， one-channel pulse density modulation， one realtime timer （RTT）， one real-time clock （RTC） and one 8-channel 12-bit ADC. The Atmel | SMART SAM G54 devices have two software-selectable low-power modes： Sleep and Wait. In Sleep mode， the processor is stopped while all other functions can be kept running. In Wait mode， all clocks and functions are stopped but some peripherals can be configured to wake up the system based on predefined conditions. This feature， called SleepWalking， performs a partial asynchronous wake-up， thus allowing the processor to wake up only when needed. The Event System allows peripherals to receive， react to and send events in Active and Sleep modes without processor intervention. A general-purpose microcontroller with the best ratio in terms of reduced power consumption， processing power and peripheral set， the SAM G54 series sustains a wide range of applications including consumer， industrial control， and PC peripherals. The device operates from 1.62V to 3.45V and is available in a 49-ball WLCSP package and a 100-pin LQFP package.