PIC16F84A INTERFACE WITH MSM6242BRS
DESCRIPTION
The MSM6242B is a silicon gate CMOS Real
Time Clock/Calendar for use in direct bus-
connection Microprocessor/Microcomputer
applications.An on-chip 32.768 kHz crystal
oscillator time base is divided to provide ad-
dressable 4-bit I/O data for SECONDS,MIN-
UTES,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 nd F provide for 30 SECOND error
adjustment,INTERRUPT REQUEST (IRQ
FLAG)and BUSY status bits,clock STOP,
HOLD,nd RESET FLAG bits,4 selectable
INTERRUPTS rates are available at the STD.P
(STANDARD PULSE)output utilizing Con-
trol Register inputs T0,T1 and the ITRPT/
STND (INTERRUPT/STANDARD).Mask-
ing of the interrupt output (STD.P)can be
accomplished via the MASK bit.The
MSM6242B can operate in a 12/24 hour for-
mat and Leap Year timing is automatic.
The MSM6242B normally operates from 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 MONTH DATE YEAR DAY OF WEEK
23:59:59 12 31 80 7
•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
•12/24 hour format
•Auto leap year
•±30 second error correction
•Single 5 V supply
•Battery backup down to V DD =2.0 V
•Low power dissipation:
20 µW max at V DD =2 V
150 µW max at V DD =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)
MSM6242B
DIRECT BUS CONNECTED CMOS REAL TIME CLOCK/CALENDAR
ATTACHED HEREWITH IS THE PDF FILE OF MSM6242BRS.