公司名称：誉诚（深圳）实业科技有限公司

Low power real-time clock and backup registersThe real-time clock (RTC) is an independent BCD timer/counter. Dedicated registers containthe second, minute, hour (12/24 hour), week day, date, month, year, in BCD (binary-codeddecimal) format. Correction for 28, 29 (leap year), 30, and 31 day of the month are madeautomatically. The RTC provides a programmable alarm and programmable periodicinterrupts with wakeup from Stop and Standby modes.●The programmable wakeup time ranges from 120 μs to 36 hours●Stop mode consumption with LSI and Auto-wakeup: 1.2 μA (at 1.8 V) and 1.4 μA (at3.0 V)●Stop mode consumption with LSE, calendar and Auto-wakeup: 1.3 μA (at 1.8V), 1.6 μA(at 3.0 V)The RTC can be calibrated with an external 512 Hz output, and a digital compensationcircuit helps reduce drift due to crystal deviation.There are twenty 32-bit backup registers provided to store 80 bytes of user application data.They are cleared in case of tamper detection.3.6GPIOs (general-purpose inputs/outputs)Each of the GPIO pins can be configured by software as output (push-pull or open-drain), asinput (with or without pull-up or pull-down) or as peripheral alternate function. Most of theGPIO pins are shared with digital or analog alternate functions, and can be individuallyremapped using dedicated AFIO registers. All GPIOs are high current capable. Thealternate function configuration of I/Os can be locked if needed following a specificsequence in order to avoid spurious writing to the I/O registers. The I/O controller isconnected to the AHB with a toggling speed of up to 16 MHz.External interrupt/event controller (EXTI)The external interrupt/event controller consists of 23 edge detector lines used to generateinterrupt/event requests. Each line can be individually configured to select the trigger event(rising edge, falling edge, both) and can be masked independently. A pending registermaintains the status of the interrupt requests. The EXTI can detect an external line with apulse width shorter than the Internal APB2 clock period. Up to 83 GPIOs can be connectedto the 16 external interrupt lines. The 7 other lines are connected to RTC, PVD, USB orComparator event