OVERVIEW

The SM8580AM is a real-time clock IC based on a 32.768 kHz crystal oscillator, which features a 4-bit paral lel interface for communication with an external microcontroller.

It comprises second-counter to year-counter clock and calendar circuits that feature automatic leap-year adjust ment 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.

FEATURES

■ High-speed bus 4-bit parallel interface

■ Date, day, hour, minute, and second-counter pre settable alarm interrupt

■ 1/4096 seconds to 255 minutes presettable interval timer interrupt function

■ 2 software-maskable alarm and timer interrupt outputs

■ Clock counter change detect functions

■ 4-digit western calendar display

■ Automatic leap year correction up to year 2099

■ ±30-second adjust function

■ −195 to +192ppm time error correction range

■ Built-in temperature sensor (analog voltage output)

■ 2.4 to 5.5V interface voltage range

■ 1.6 to 5.5V clock voltage range

■ 0.6µA/3V (typ) current consumption