説明The DS1384 Watchdog Timekeeping Controller integrates critical processor and memory support functions: real-time clock/calendar in BCD format, clock/calendar alarms, interval timer, and watchdog timer with processor restart. The DS1384 further integrates controller circuitry to monitor power to 128k x 8 external static SRAM with automatic backup switching and write protection. Additionally, 50 bytes of user RAM are available for system configuration, calibration data, or scratchpad.
Clock and alarm settings are programmed and on-chip memory is addressed through a bytewide interface. The clock data can be output in either 24-hour or 12-hour format with a.m./p.m. indicator.
The DS1384 connects to a 32.768kHz crystal for a clock reference and battery for backup; no external capacitors or resistors are required. Dallas timekeepers operate with the lowest power consumption in the industry, consuming less than 0.5µA while maintaining accurate and reliable timekeeping on battery power.
- Real-time clock/calendar: tracks hundredths of seconds, seconds, minutes, hours, days, date, months, years, and leap years
- Accuracy >±2 minutes/month at 25°C
- Watchdog timer monitors/restarts processor
- Programmable time-of-day and real-time watchdog alarms
- Interrupt outputs active during battery backup mode
- Controller circuitry supports up to 128k x 8 external SRAM
- All registers individually addressed through bytewide interface
- 50 bytes of user NV RAM
- Low-power CMOS circuitry: <1µA battery current in standby mode
- Square wave outputs
- Operating range: 0°C to +70°C
- Voltage/power-fail tolerance: 5V ±10%
- Highly Accurate RTC with Integrated MEMS Resonator Completely Manages All Timekeeping Functions
- 64-Byte RAM for User Data Storage
- Simple Serial Interface Connects to Most Microcontrollers