DS1384

Watchdog Real Time Clocks Controller

Viewing:

Overview

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%

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.