MSM6242B

The MSM6242B is a silicon gate CMOS Real Time Clock/Calendar for use in direct busconnection Microprocessor/Microcomputer applications. An on-chip 32.768 KHz crystal oscillator time base is divided to provide addressable 4-bit I/O data for SECONDS,MINUTES, HOURS, DAY OF WEEK, DATE,MONTH and YEAR. Data access is controlled by 4-bit address, chip selects (CSO, CS1),WRITE, READ, and ALE. Control Registers D, E and F provide for 30 SECOND error adjustment, INTERRUPT REQUEST (IRQ FLAG) and BUSY status bits, clock STOP,HOLD, and RESET FLAG bits, 4 selectable INTERRUPTS rates are available at the STD.P (STANDARD PULSE) output utilizing Control Register inputs T0, T1 and the ITRPT/ STND (INTERRUPT/STANDARD). Masking of the interrupt output (STD.P) can be accomplished via the MASK bit. The MSM6242B can operate in a 12/24 hour format and Leap Year timing is automatic.

The MSM6242B normally operates from a 5V ±10% supply at 40 to 85°C. Battery backup operation down to 2.0V allows continuation of time keeping when main power is off. The MSM6242B is offered in a 18-pin plastic DIP and a 24-pin plastic Small Outline package.