ONDA SOM/ONDA Hardware/Peripherals/RTC
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| 2026/03/11 | First documentation release | ||
Contents
Peripheral RTC[edit | edit source]
An on-board Maxim Integrated DS3232M device provides a very accurate, temperature-compensated real-time clock (RTC) resource with:
- Temperature-compensated crystal oscillator
- Date, time and calendar
- Alarm capability
- Backup power from external battery
- ±3.5ppm accuracy from -40°C to +85°C
- 236 Bytes of Battery-Backed SRAM
- I²C Interface
For a detailed description of RTC characteristics, please refer to the DS3232M datasheet.
Signals[edit | edit source]
| Pin# | Pin name | Function | Notes |
|---|---|---|---|
| J2.93 | RTC_32KHZ | 32.768kHz output | - |
| J2.95 | RTC_RSTn | active-low reset | open-drain input/output |
| J2.111 | RTC_INTn/SQW | active-Low Interrupt or 1Hz Square-Wave Output | It can be left open if not used. |
| J2.113 | RTC_VBAT | Backup power | If not used, RTC_VBAT must be externally connected to GND |
