3.3 V /1/2/4 DC-DC LDOs OSC PLL RF conversion UART I2C GPIOs SPI POR 法律流程外包 Watchdog 安全 ROM RAM ADCs DACs PD PD VGA ARM Cortex DA4100 晶体 BLE to PA from PA 1V to 1.2 V EEPROM PD VGA to PA CLK_OUT