February 2002
5-65
STK16C88
32K x 8 AutoStorePlus™ nvSRAM
QuantumTrap™ CMOS
Nonvolatile Static RAM
FEATURES
• Transparent Data Save on Power Down
• Internal Capacitor Guarantees AutoStore™
Regardless of Power-Down Slew Rate
• Nonvolatile Storage without Battery Problems
• Directly Replaces 32K x 8 Static RAM, Battery-
Backed RAM or EEPROM
• 25ns, 35ns and 45ns Access Times
• STORE to EEPROM Initiated by Software or
AutoStorePlus™ on Power Down
• No Data Loss from Undershoot
• RECALL to SRAM Initiated by Software or
Power Restore
• 10mA Typical I
CC at 200ns Cycle Time
• Unlimited READ, WRITE and RECALL Cycles
• 1,000,000 STORE Cycles to EEPROM
• 100-Year Data Retention over Full Industrial
Temperature Range
• Commercial and Industrial Temperatures
• 28-Pin PDIP Package
DESCRIPTION
The STK16C88 is a fast SRAM with a nonvolatile
EEPROM
element incorporated in each static mem-
ory cell. The SRAM can be read and written an
unlimited number of times, while independent non-
volatile data resides in EEPROM. Data transfers from
the SRAM to the EEPROM (the STORE operation) can
take place automatically on power down. An internal
capacitor guarantees the STORE operation regard-
less of power-down slew rate. Transfers from the
EEPROM
to the SRAM (the RECALL operation) take
place automatically on restoration of power. Initia-
tion of STORE and RECALL cycles can also be con-
trolled by entering control sequences on the SRAM
inputs. The STK16C88 is pin-compatible with 32k x
8 SRAMs and battery-backed SRAMs, allowing direct
substitution while enhancing performance. The
STK14C88, which uses an external capacitor, and
the STK15C88, which uses charge stored in system
capacitance, are alternatives for systems needing
AutoStorePlus™ operation.
BLOCK DIAGRAM
EEPROM ARRAY
512 x 512
STORE
RECALL
COLUMN I/O
COLUMN DEC
STATIC RAM
ARRAY
512 x 512
STORE/
RECALL
CONTROL
POWER
CONTROL
A6
A7
A11
A12
A13
A14
DQ0
DQ1
DQ2
DQ3
DQ4
DQ5
DQ6
DQ7
SOFTWARE
DETECT
VCC
A0 - A13
G
E
W
A9
A8
A10
A3
A2
A0 A1
A4
A5
INTERNAL
CAPACITOR
PIN CONFIGURATIONS
A14
A12
A7
A6
A5
A4
A3
A2
A1
A0
DQ0
DQ1
DQ2
VSS
VCC
A13
A8
A9
A11
G
W
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
A10
E
DQ7
DQ6
DQ5
DQ4
DQ3
28 - 600 PDIP
PIN NAMES
A0 - A14
Address Inputs
W
Write Enable
DQ0 - DQ7
Data In/Out
E
Chip Enable
G
Output Enable
VCC
Power (+ 5V)
VSS
Ground