DA14581 QDEC ADC 醒来 键盘 定时器 ARM M0 CPU XTAL16M 无线电 数字PHY BLE 4.2 MAC就绪 XTAL32K RC32KHz RC16KHz RCX DCDC BUCK DCDC BOOST 只读存储器 84 KB 低压降稳压器 社署 UARTx2 SPI I2C OTP 32 KB RAM 42 KB 保留 RAM 8 KB GPIO矩阵