DESCRIPTION
The MSM 58321 is a metal gate CMOS Real Time Clock/Calendar with a battery backup function for use in bus-oriented microprocessor applications.
The 4-bit bidirectional bus line method is used for the data I/O circuit; the clock is set, corrected, or read by accessing the memory.

The time is read with 4-bit DATA I/O, ADDRESS WRITE, READ, and BUSY; it is written with 4-bit DATA I/O, ADDRESS WRITE, WRITE, and BUSY.

FEATURES
• 7 Function-Second, Minute, Hour, Day, Day-of-Week, Month, Year 

• Automatic leap year calendar 

• 12/24 hour format 

• Frequency divider 5-poststage reset 

• Reference signal output

• 32.768 kHz crystal controlled operation 

• Single 5V power supply 

• Back-up battery operation to VDD = 2.2V 

• Low power dissipation 90 µW max. at VDD = 3V 2.5 mW max. at VDD = 5V 

• 16 pin plastic DIP (DIP 16-P-300)