Features: SpecificationsDescriptionThe HD64610 has the following features including 8-bit data bus (static-RAM interface); high-speed static-RAM timing equivalent to HM62256;Oscillator circuit(Rf, Rd) incorporated;Timer and calendar functions (BCD based);second, minute, hour, date, day of week,month, and year counters;30-second ADJUST function;Alarm interrupt and carry interrupt;1 Hz output;Leap year automatic adjustment;Battery backup (low power operation capability).
The HD64610 is a calendar clock IC providing calendar clock functions and an 8-bit static-RAM interface. The HD64610 incorporates a crystal oscillator circuit dedicated to 32 kHz and a voltage clamp circuit enabling low current dissipation and battery back-up.The HD64610 generates a 1 Hz basic signal through a crystal oscillator (32.768 kHz) and a divider circuit. A divider circuits provides a detail clock data ranging from 64 Hz to 1 Hz, which can be read through the 64 Hz counter. A carry occurs and the clock data is updated on every 1 Hz interval in the second, minute, hour, day of week,date, month, and year counters. It is thus necessary to confirm that no carry has occurred during counter reading since the counter value is undefined when a carry occurs. Whether or not a carry has occurred can be checked by carry flag or interrupt.
An alarm can be generated any time under the control of the 64 Hz, second, minute, hour, day of week, and date alarm registers. Alarm time can be specified by setting the appropriate enable (ENB) bits and time bits of alarm registers. Whether or not an alarm has occurred can be confirmed by reading the alarm flag in control register A or by interrupt. Start/stop, reset, and 30-second adjustment of the divider circuit are also provided for clock counter control.The HD64610 features a 64 Hz counter, which counts time in cycles from b4 Hz to 1 Hz provided from the divider circuit, and second,minute, hour, day of week, date, month, and year counters for calendar clock function.These HD64610 counters are constructed by a series of ripple counters.
HD64610 Data Sheet
