Note: Built-in 5V to 3.3V,3.3V to 1.2V LDO to power the chip Built-in POR (Power on Reset), low voltage detection and watchdog Support I2C, DAC, PWM and multiple interfaces Support fast and convenient UART, I2C and other control protocol development Built-in 242KB high-speed SRAM, 2MB FLASH Flexible configuration supports 1.8/2.8/3.3V IO Support for a 1 analog Mic input, SNR294db Support dual-channel DAC output