The SM8580A is a real-time clock IC based on a 32.768kHz crystal oscillator, which features a 4-bit parallel interface for communication with an external microcontroller. It comprises second-counter to year-counter clock and calendar circuits that feature automatic leap-year adjustment up to year 2099, alarm and timer interrupt functions, clock counter change detect functions, ±30-second correction function, time error correction function, and built-in temperature sensor. The 4-bit parallel interface is compatible with general-purpose SRAM over a high-speed bus.
Key Features
High-speed bus 4-bit parallel interface
Built-in temperature sensor (analog voltage output)
-195 to +192ppm time error correction range
2 alarm and timer interrupt outputs-(software override when desired)
Date, day, hour, minute, and second-counter pre-settable alarm interrupt
1/4096 seconds to 255 minutes pre-settable interval timer interrupt function
SM8580A.pdf