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STK1744 Datasheet, PDF (1/12 Pages) List of Unclassifed Manufacturers – 32K x 8 AutoStore nvSRAM with Real-Time Clock
STK1744
nvTime™
32K x 8 AutoStore™ nvSRAM
with Real-Time Clock
FEATURES
• Data Integrity of Simtek nvSRAM Combined
with Full-Featured Real-Time Clock
• Stand-Alone Nonvolatile Memory and Time-
Keeping Solution—No Other Parts Required
• No Batteries to Fail
• Fast 25ns, 35ns and 45ns Access Times
• Software- and AutoStore™-Controlled
Nonvolatile Cycles
• Year 2000 Compliant with Leap Year
Compensation
• 24-Hour BCD Format
• 100-Year Data Retention over Full Industrial
Temperature Range
• Full 30-Day RTC Operation on Each Power
Loss
• Single 5V ± 10% Power Supply
DESCRIPTION
PRELIMINARY
The Simtek STK1744 DIP module houses 256Kb of
nonvolatile static RAM, a real-time clock (RTC) with
crystal and a high-value capacitor to support sys-
tems that require high reliability and ease of manu-
facturing. READ and WRITE access to all RTC
functions and the memory is the same as a conven-
tional x 8 SRAM. The highest eight addresses of the
RAM support clock registers for centuries, years,
months, dates, days, hours, minutes and seconds.
Independent data resides in the integral Nonvolatile
Elements at all times. Automatic RECALL on power
up transfers the Nonvolatile Elements data to the
SRAM, while an automatic STORE on power down
transfers SRAM data to the Nonvolatile Elements. A
software RECALL and STORE are also possible on
user command. nvTime™ allows unlimited READ
and WRITE accesses to SRAM, unlimited RECALLs
and 106 STOREs.
BLOCK DIAGRAM
A5
A6
A7
A8
A9
A11
A12
A13
A14
DQ0
DQ1
DQ2
DQ3
DQ4
DQ5
DQ6
DQ7
QUANTUM TRAP
512 x 512
STATIC RAM
ARRAY
512 x 512
STORE
RECALL
COLUMN I/O
COLUMN DEC
A0 A1 A2 A3 A4A10
VCC
STORE/
RECALL
CONTROL
POWER
CONTROL
SOFTWARE
DETECT
A0 - A13
PIN CONFIGURATIONS
A14 1
A12 2
A7 3
A6 4
A5 5
A4 6
A3 7
A2 8
A1 9
A0 10
DQ0 11
DQ1 12
DQ2 13
VSS 14
28 VCC
27 W
26 A13
25 A8
24 A9
23 A11
22 G
21 A10
20 E
19 DQ7
18 DQ6
17 DQ5
16 DQ4
15 DQ3
28 - 600 DIP
Module
(See application
note for surface
mount)
RTC
MUX
A0 -
A14
PIN NAMES
A0 - A14
W
Address Inputs
Write Enable
DQ0 - DQ7
Data In/Out
E
G
G
Chip Enable
Output Enable
E
VCC
Power (+ 5V)
W
VSS
Ground
January 2003
1 Document Control # ML0020 rev 0.0