DS1397

www.DataSheet4U.com DS1395/DS1397 DS1395/DS1397 RAMified Real Time Clock FEATURES PIN ASSIGNMENT A0 A1 X2 X1 STBY D0 D1 D2 D3 D4 D5 D6 D7 V SS 1 2 3 4 5 6 7 8 9 10 11 12 13 14 28 27 26 25 24 23 22 21 20 19 18 17 16 15 A2 A3 VDD SQW A4 A5 VBAT IRQ RESET RD BGND WR XRAM RTC Ideal for EISA bus PCs Functionally compatible mode with MC146818 in 32 KHz Totally nonvolatile with over 10 years of operation in the absence of power Self-contained Counts subsystem includes lithium, quartz, and support circuitry seconds, minutes, hours, day of the week, date, month, and year with leap year compensation alarm Binary or BCD representations of time, calendar, and 12- or 24-hour clock with AM and PM in 12-hour mode Daylight Savings Time option Interfaced with software as 64 register/RAM locations plus 4K x 8 of static RAM – 14 bytes of clock and control registers – 50 bytes of general and control registers – Separate 4K x 8 nonvolatile SRAM DS1395S 28-Pin SOIC (330 mil) A0 A1 X2 X1 STBY D0 D1 D2 D3 D4 D5 D6 D7 VSS 1 2 3 4 5 6 7 8 9 10 11 12 13 14 28 27 26 25 24 23 22 21 20 19 18 17 16 15 A2 A3 VDD SQW A4 A5 VBAT IRQ RESET RD BGND WR XRAM RTC Programmable square wave output signal Bus-compatible interrupt signals (IRQ) Three interrupts are separately software-maskable and testable: – Time-of-day alarm once/second to once/day – Periodic rates from 122 µs to 500 ms – End-of-clock update cycle DS1395 28-Pin DIP (600 mil) A0 A1 NC NC STBY D0 D1 D2 D3 D4 D5 D6 D7...