Rainbow Electronics DS1691 - Manual

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FEATURES
Incorporates industry standard DS1287 PC clock
plus enhanced features:
+3 or +5V operation
64–bit Silicon serial number
64–bit customer specific ROM or additional
serial number available
Power control circuitry supports system
power on from date/time alarm or key closure
Automatic battery backup and write
protection to external SRAM
Crystal select bit allows RTC to operate with
6 pF or 12.5 pF crystal
114 bytes user NV RAM
Auxiliary battery input
RAM clear input
Century register
32 kHz output for power management
32–bit V
CC
powered elapsed time counter
32–bit V
BAT
powered elapsed time counter
16–bit power cycle counter
Compatible with existing BIOS for original
DS1287 functions
Available as IC (DS1688) or stand–alone
module with embedded battery and crystal
(DS1691)
Timekeeping algorithm includes leap year
compensation valid up to 2100
ORDERING INFORMATION
PART # DESCRIPTION
DS1688S RTC IC, 28–pin SOIC
DS1691 RTC Module; 28–pin DIP
PIN ASSIGNMENT
PIN DESCRIPTION
X1 - Crystal Input
X2 - Crystal Output
RCLR - RAM Clear Input
AD0-AD7 - Mux’ed Address/Data Bus
PWR - Power-on Interrupt Output
KS - Kickstart Input
CS - RTC Chip Select Input
ALE - RTC Address Strobe
WR - RTC Write Data Strobe
RD - RTC Read Data Strobe
V
CCO
- RAM Power Supply Output
DS1688/DS1691
3 Volt/5 Volt Serialized Real Time Clock
with NV RAM Control
www.dalsemi.com