MSM6542-01

¡ Semiconductor MSM6542-01/02/03 MSM6542-01/02/03 DESCRIPTION The MSM6542 is a perpetual-calendar-based real time clock with an alarm function which can read and write data in units of seconds. It can be connected to various buses and can function as a peripheral IC of a microcomputer. The clock ranges are seconds, minutes, hours, days, months, years, and days of the week. The alarm ranges are seconds, minutes, hours, www.DataSheet4U.com days, months, and days of the week. An event trigger is generated when the time matches the specified time and an alarm occurs or when the clock counter generates a carry. The interrupt and pulse outputs are provided for each of an alarm and a carry. An interface with a microcomputer is implemented by four data bus pins, four address bus ¡ Semiconductor REAL TIME CLOCK WITH PERIODIC AND ALARM OUTPUT bus pins, three control bus pins, and two chip select pins. These pins are used to write or read data from the clock, alarm, and control registers, or to modify the data. The MSM6542 has an address latch enable (ALE) input pin, allowing the data bus and address bus to be shared. When the ALE input pin is kept high, the data bus and address bus can be exclusively used. Other functions of the MSM6542 are: a 30second adjustment, stop and restart of clock, data registers as RAM, and data register (RAM) protection. The CMOS circuitry used in the MSM6542 affords low power dissipation. The crystal oscillator operates at 32.768 kHz. Provisions for back...