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M6242B OKI (RTC)


OKI M6242B

… Real Time Clock (RTC) – Amiga-Uhrenbaustein

OKI M6242B für: - z.B. A500, A500+, A2000
und auch diverse Speicher- bzw. Prozessor-Karten


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 ¡ Semiconductor MSM6242B DIRECT BUS CONNECTED CMOS REAL TIME CLOCK/CALENDAR (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.


  • 4-bit data bus
  • 4-bit address bus
  • 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 5V supply
  • Battery backup down to VDD = 2.0V
  • Low power dissipation:
    20μW max at VDD = 2V
    150μW max at VDD = 5V
  • 18 pin Plastic DIP (DIP18-P-300)
  • 24 Pin-V Plastic SOP (SOP24-P-430-VK)

Pinbelegung / Pinout

OKI M6242B

im Amiga

TypCommo-Nr. C= Bezeichnung C= Info Form Editors Info
A 318073-01IC 6242 REAL TIME CL.AMIGA-500DIP-18

VorkommenAnzahlTypPosition Bemerkung
Axx 1 A U,-
Axx 1 A U,-

Downloads / Links

Zuletzt geändert: 2013/09/25 23:59