General Description
●The CMOS bq3287/bq3287A is a low-power microprocessor peripheral providing a time-of-day clock
●and 100-year calendar with alarm features and battery operation. Other features include three
●maskable interrupt sources, square wave output, and 114 bytes of gen eral nonvolatile storage.
●Features
●➤Direct clock/calendar replacement for IBM® AT-compatible computers and other applications
●➤Functionally compatible with the DS1287/DS1287A and MC146818A
●➤114 bytes of general nonvolatile storage
●➤Integral lithium cell and crystal
●➤160 ns cycle time allows fast bus operation
●➤Selectable Intel or Motorola bus timing
●➤14 bytes for clock/calendar and control
●➤BCD or binary format for clock and calendar data
●➤Time of day in seconds, minutes, and hours
● - 12- or 24-hour format
● - Optional daylight saving adjustment
●➤Calendar in day of the week, day of the month, months, and years with automatic leap-year adjust
●ment
●➤Programmable square wave out put
●➤Three individually maskable in terrupt event flags:
● - Periodic rates from 122µs to 500 ms
● - Time-of-day alarm once per second to once per day
● - End-of-clock update cycle
●➤Better than one minute per month clock accuracy
