FEDL6242B-02
MSM6242B
OKI Semiconductor
OKI Semiconductor
MSM6242B
FEDL6242B-02
Issue Date: Jun. 17, 2002
DIRECT BUS CONNECTED CMOS REAL TIME CLOCK/CALENDAR
DESCRIPTION
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 (CS0, 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 5 V
±10% supply at –40 to +85°C. Battery backup
operation down to 2.0 V 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.
FEATURES
DIRECT MICROPROCESSOR/MICROCONTROLLER BUS CONNECTION
TIME
23:59:59
MONTH
DATE
12
31
• 4-bit data bus
• 4-bit address bus
• READ, WRITE, ALE and CHIP SELECT
INPUTS
• Status registers – IRQ and BUSY
• Selectable interrupt outputs – 1/64
second, 1 second, 1 minute, 1 hour
• Interrupt masking
• 32.768 kHz crystal controlled operation
YEAR
80
•
•
•
•
•
•
DAY OF WEEK
7
12/24 hour format
Auto leap year
±30 second error correction
Single 5 V supply
Battery backup down to VDD = 2.0 V
Low power dissipation:
20 µW max at VDD = 2 V
150 µW max at VDD = 5 V
• Package: 18-pin plastic DIP (DIP18-P-300-2.54) (MSM6242BRS)
24-pin plastic SOP (SOP24-P-430-1.27-K) (MSM6242BGS-K)
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