STK12C68-5 (SMD5962-94599)
64 Kbit (8K x 8) AutoStore nvSRAM
Features
Functional Description
■ 35 ns and 55 ns access times
The Cypress STK12C68-5 is a fast static RAM with a nonvol-
atile element in each memory cell. The embedded nonvolatile
■ Hands off automatic STORE on power down with external
68 µF capacitor
elements incorporate QuantumTrap technology producing the
world’s most reliable nonvolatile memory. The SRAM provides
unlimited read and write cycles, while independent nonvolatile
data resides in the highly reliable QuantumTrap cell. Data
transfers from the SRAM to the nonvolatile elements (the
STORE operation) takes place automatically at power down.
On power up, data is restored to the SRAM (the RECALL
operation) from the nonvolatile memory. Both the STORE and
RECALL operations are also available under software control.
A hardware STORE is initiated with the HSB pin.
■ STORE to QuantumTrap™ nonvolatile elements is initiated
by software, hardware, or AutoStore™ on power down
■ RECALL to SRAM initiated by software or power up
■ Unlimited Read, Write, and Recall cycles
■ 1,000,000 STORE cycles to QuantumTrap
■ 100 year data retention to QuantumTrap
■ Single 5V+10% operation
■ Military temperature
■ 28-pin (300mil) CDIP and 28-pad LCC packages
Logic Block Diagram
V
V
CC
CAP
Quantum Trap
128 X 512
A5
POWER
STORE
CONTROL
A6
A7
RECALL
STORE/
RECALL
CONTROL
STATIC RAM
ARRAY
128 X 512
A8
HSB
A9
A11
A12
SOFTWARE
DETECT
A0 -A12
DQ0
COLUMN I/O
DQ1
DQ2
DQ3
COLUMN DEC
DQ4
DQ5
A0
A4
A10
A1
A3
A2
DQ6
DQ7
OE
CE
WE
Cypress Semiconductor Corporation
Document Number: 001-51026 Rev. **
•
198 Champion Court
•
San Jose, CA 95134-1709
•
408-943-2600
Revised March 02, 2009
STK12C68-5 (SMD5962-94599)
During normal operation, the device draws current from V to
Device Operation
CC
charge a capacitor connected to the V
pin. This stored
CAP
charge is used by the chip to perform a single STORE operation.
If the voltage on the V pin drops below V , the part
The STK12C68-5 nvSRAM is made up of two functional compo-
nents paired in the same physical cell. These are an SRAM
memory cell and a nonvolatile QuantumTrap cell. The SRAM
memory cell operates as a standard fast static RAM. Data in the
SRAM is transferred to the nonvolatile cell (the STORE
operation) or from the nonvolatile cell to SRAM (the RECALL
operation). This unique architecture enables the storage and
recall of all cells in parallel. During the STORE and RECALL
operations, SRAM Read and Write operations are inhibited. The
STK12C68-5 supports unlimited reads and writes similar to a
typical SRAM. In addition, it provides unlimited RECALL opera-
tions from the nonvolatile cells and up to one million STORE
operations.
CC
SWITCH
automatically disconnects the V
operation is initiated with power provided by the V
pin from V . A STORE
CAP
CC
capacitor.
CAP
Figure 3 shows the proper connection of the storage capacitor
(V ) for automatic store operation. A charge storage capacitor
CAP
between 68 µF and 220 µF (+20%) rated at 6V must be provided.
The voltage on the V pin is driven to 5V by a charge pump
CAP
internal to the chip. A pull up is placed on WE to hold it inactive
during power up.
Figure 3. AutoStore Mode
SRAM Read
The STK12C68-5 performs a Read cycle whenever CE and OE
are LOW while WE and HSB are HIGH. The address specified
9&$3
9FF
on pins A
determines the 8,192 data bytes accessed. When
0–12
the Read is initiated by an address transition, the outputs are
valid after a delay of t (Read cycle 1). If the Read is initiated
:(
AA
+6%
by CE or OE, the outputs are valid at t
or at t
, whichever
ACE
DOE
is later (Read cycle 2). The data outputs repeatedly respond to
address changes within the t access time without the need for
AA
transitions on any control input pins, and remains valid until
another address change or until CE or OE is brought HIGH, or
WE or HSB is brought LOW.
SRAM Write
A Write cycle is performed whenever CE and WE are LOW and
HSB is HIGH. The address inputs must be stable prior to entering
the Write cycle and must remain stable until either CE or WE
goes HIGH at the end of the cycle. The data on the common IO
pins DQ
are written into the memory if it has valid t , before
0–7
SD
9VV
the end of a WE controlled Write or before the end of an CE
controlled Write. Keep OE HIGH during the entire Write cycle to
avoid data bus contention on common IO lines. If OE is left LOW,
internal circuitry turns off the output buffers t
LOW.
after WE goes
In system power mode, both V and V
are connected to the
CAP
CC
HZWE
+5V power supply without the 68 μF capacitor. In this mode, the
AutoStore function of the STK12C68-5 operates on the stored
system charge as power goes down. The user must, however,
AutoStore Operation
guarantee that V does not drop below 3.6V during the 10 ms
CC
The STK12C68-5 stores data to nvSRAM using one of three
storage operations:
STORE cycle.
To reduce unnecessary nonvolatile stores, AutoStore, and
Hardware Store operations are ignored, unless at least one Write
operation has taken place since the most recent STORE or
RECALL cycle. Software initiated STORE cycles are performed
regardless of whether a Write operation has taken place. An
optional pull up resistor is shown connected to HSB. The HSB
signal is monitored by the system to detect if an AutoStore cycle
is in progress.
1. Hardware store activated by HSB
2. Software store activated by an address sequence
3. AutoStore on device power down
AutoStore operation is a unique feature of QuantumTrap
technology and is enabled by default on the STK12C68-5.
Document Number: 001-51026 Rev. **
Page 3 of 18
STK12C68-5 (SMD5962-94599)
Figure 4. AutoStore Inhibit Mode
During any STORE operation, regardless of how it is initiated,
the STK12C68-5 continues to drive the HSB pin LOW,
releasing it only when the STORE is complete. After
completing the STORE operation, the STK12C68-5 remains
disabled until the HSB pin returns HIGH.
9&$3
9FF
:(
If HSB is not used, it is left unconnected.
Hardware RECALL (Power Up)
+6%
During power up or after any low power condition (V
<
CC
V
), an internal RECALL request is latched. When V
RESET
CC
once again exceeds the sense voltage of V
, a RECALL
SWITCH
cycle is automatically initiated and takes t
to complete.
HRECALL
If the STK12C68-5 is in a Write state at the end of power up
RECALL, the SRAM data is corrupted. To help avoid this
situation, a 10 Kohm resistor is connected either between WE
and system V or between CE and system V
.
CC
CC
Software STORE
Data is transferred from the SRAM to the nonvolatile memory
by a software address sequence. The STK12C68-5 software
STORE cycle is initiated by executing sequential CE controlled
Read cycles from six specific address locations in exact order.
During the STORE cycle, an erase of the previous nonvolatile
data is first performed followed by a program of the nonvolatile
elements. When a STORE cycle is initiated, input and output
are disabled until the cycle is completed.
9VV
If the power supply drops faster than 20 us/volt before Vcc
reaches V
between V
, then a 2.2 ohm resistor must be connected
and the system supply to avoid momentary
SWITCH
CC
Because a sequence of Reads from specific addresses is
used for STORE initiation, it is important that no other Read or
Write accesses intervene in the sequence. If they intervene,
the sequence is aborted and no STORE or RECALL takes
place.
excess of current between V and V
.
CC
CAP
AutoStore Inhibit Mode
If an automatic STOREon power loss is not required, then V
CC
is tied to ground and +5V is applied to V
the AutoStore Inhibit mode, where the AutoStore function is
disabled. If the STK12C68-5 is operated in this configuration,
CAP
To initiate the software STORE cycle, the following Read
sequence is performed:
1. Read address 0x0000, Valid READ
2. Read address 0x1555, Valid READ
3. Read address 0x0AAA, Valid READ
4. Read address 0x1FFF, Valid READ
5. Read address 0x10F0, Valid READ
6. Read address 0x0F0F, Initiate STORE cycle
references to V are changed to V
throughout this data
CAP
CC
sheet. In this mode, STORE operations are triggered through
software control or the HSB pin. To enable or disable Autostore
permissible to change between these three options “on the
fly”.
Hardware STORE (HSB) Operation
The software sequence is clocked with CE controlled Reads
or OE controlled Reads. When the sixth address in the
sequence is entered, the STORE cycle commences and the
chip is disabled. It is important that Read cycles and not Write
cycles are used in the sequence. It is not necessary that OE
The STK12C68-5 provides the HSB pin for controlling and
acknowledging the STORE operations. The HSB pin is used
to request a hardware STORE cycle. When the HSB pin is
driven LOW, the STK12C68-5 conditionally initiates a STORE
is LOW for a valid sequence. After the t
cycle time is
STORE
operation after t
. An actual STORE cycle only begins if a
DELAY
fulfilled, the SRAM is again activated for Read and Write
operation.
Write to the SRAM takes place since the last STORE or
RECALL cycle. The HSB pin also acts as an open drain driver
that is internally driven LOW to indicate a busy condition, while
the STORE (initiated by any means) is in progress.
Software RECALL
Data is transferred from the nonvolatile memory to the SRAM
by a software address sequence. A software RECALL cycle is
initiated with a sequence of Read operations in a manner
similar to the software STORE initiation. To initiate the
RECALL cycle, the following sequence of CE controlled Read
operations is performed:
SRAM Read and Write operations, that are in progress when
HSB is driven LOW by any means, are given time to complete
before the STORE operation is initiated. After HSB goes LOW,
the STK12C68-5 continues SRAM operations for t
.
DELAY
During t
, multiple SRAM Read operations take place. If
DELAY
a Write is in progress when HSB is pulled LOW, it allows a
time, t to complete. However, any SRAM Write cycles
requested after HSB goes LOW are inhibited until HSB returns
HIGH.
1. Read address 0x0000, Valid READ
2. Read address 0x1555, Valid READ
3. Read address 0x0AAA, Valid READ
DELAY
Document Number: 001-51026 Rev. **
Page 4 of 18
STK12C68-5 (SMD5962-94599)
4. Read address 0x1FFF, Valid READ
5. Read address 0x10F0, Valid READ
6. Read address 0x0F0E, Initiate RECALL cycle
Figure 5. Current Versus Cycle Time (Read)
Internally, RECALL is a two step procedure. First, the SRAM data
is cleared; then, the nonvolatile information is transferred into the
SRAM cells. After the t
cycle time, the SRAM is again
RECALL
ready for Read and Write operations. The RECALL operation
does not alter the data in the nonvolatile elements. The nonvol-
atile data can be recalled an unlimited number of times.
Data Protection
The STK12C68-5 protects data from corruption during low
voltage conditions by inhibiting all externally initiated STORE
and Write operations. The low voltage condition is detected
when V is less than V
. If the STK12C68-5 is in a Write
CC
SWITCH
mode (both CE and WE are low) at power up after a RECALL or
after a STORE, the Write is inhibited until a negative transition
on CE or WE is detected. This protects against inadvertent writes
during power up or brown out conditions.
Figure 6. Current Versus Cycle Time (Write)
Noise Considerations
The STK12C68-5 is a high speed memory. It must have a high
frequency bypass capacitor of approximately 0.1 µF connected
between V and V
using leads and traces that are as short
CC
SS,
as possible. As with all high speed CMOS ICs, careful routing of
power, ground, and signals reduce circuit noise.
Hardware Protect
The STK12C68-5 offers hardware protection against inadvertent
STORE operation and SRAM Writes during low voltage condi-
tions. When V
<V
, all externally initiated STORE
CAP
SWITCH
operations and SRAM Writes are inhibited. AutoStore can be
completely disabled by tying VCC to ground and applying +5V to
Preventing Store
V
. This is the AutoStore Inhibit mode; in this mode, STOREs
are only initiated by explicit request using either the software
sequence or the HSB pin.
CAP
The STORE function is disabled by holding HSB high with a
driver capable of sourcing 30 mA at a V
of at least 2.2V,
OH
because it must overpower the internal pull down device. This
device drives HSB LOW for 20 μs at the onset of a STORE.
When the STK12C68-5 is connected for AutoStore operation
Low Average Active Power
CMOS technology provides the STK12C68-5 the benefit of
drawing significantly less current when it is cycled at times longer
(system V connected to V and a 68 μF capacitor on V )
CC
crosses V
CC
CAP
and V
on the way down, the STK12C68-5
CC
SWITCH
attempts to pull HSB LOW. If HSB does not actually get below
between I and Read or Write cycle time. Worst case current
CC
V , the part stops trying to pull HSB LOW and abort the STORE
consumption is shown for both CMOS and TTL input levels
(commercial temperature range, VCC = 5.5V, 100% duty cycle
on chip enable). Only standby current is drawn when the chip is
disabled. The overall average current drawn by the STK12C68-5
depends on the following items:
IL
attempt.
■ The duty cycle of chip enable
■ The overall cycle rate for accesses
■ The ratio of Reads to Writes
■ CMOS versus TTL input levels
■ The operating temperature
■ The V level
CC
Document Number: 001-51026 Rev. **
Page 5 of 18
STK12C68-5 (SMD5962-94599)
■ Power up boot firmware routines must rewrite the nvSRAM
into the desired state. While the nvSRAM is shipped in a
preset state, best practice is to again rewrite the nvSRAM
into the desired state as a safeguard against events that
might flip the bit inadvertently (program bugs, incoming
inspection routines, and so on).
Best Practices
nvSRAM products have been used effectively for over 15
years. While ease-of-use is one of the product’s main system
values, experience gained working with hundreds of applica-
tions has resulted in the following suggestions as best
practices:
■ The Vcap value specified in this data sheet includes a
minimum and a maximum value size. The best practice is to
meet this requirement and not exceed the maximum Vcap
value because the higher inrush currents may reduce the
reliability of the internal pass transistor. Customers who want
to use a larger Vcap value to make sure there is extra store
charge must discuss their Vcap size selection with Cypress.
■ The nonvolatile cells in an nvSRAM are programmed on the
test floor during final test and quality assurance. Incoming
inspection routines at customer or contract manufacturer’s
sites sometimes reprograms these values. Final NV patterns
are typically repeating patterns of AA, 55, 00, FF, A5, or 5A.
The end product’s firmware must not assume that an NV
array is in a set programmed state. Routines that check
memory content values to determine first time system config-
uration, cold or warm boot status, and so on must always
program a unique NV pattern (for example, complex 4-byte
pattern of 46 E6 49 53 hex or more random bytes) as part of
the final system manufacturing test to ensure these system
routines work consistently.
Table 1. Hardware Mode Selection
CE
H
L
WE
X
HSB
H
A12–A0
Mode
IO
Power
X
X
X
X
Not Selected
Read SRAM
Write SRAM
Output High Z
Output Data
Input Data
Standby
H
H
Active
L
L
H
Active
[1]
X
X
L
Nonvolatile STORE Output High Z
I
CC2
L
H
H
0x0000
0x1555
0x0AAA
0x1FFF
0x10F0
0x0F0F
Read SRAM
Read SRAM
Read SRAM
Read SRAM
Read SRAM
Output Data
Output Data
Output Data
Output Data
Output Data
Active I
CC2
Nonvolatile STORE Output High Z
L
H
H
0x0000
0x1555
0x0AAA
0x1FFF
0x10F0
0x0F0E
Read SRAM
Read SRAM
Read SRAM
Read SRAM
Read SRAM
Output Data
Output Data
Output Data
Output Data
Output Data
Active
Nonvolatile RECALL Output High Z
Notes
1. HSB STORE operation occurs only if an SRAM Write is done since the last nonvolatile cycle. After the STORE (If any) completes, the part goes into standby
mode, inhibiting all operations until HSB rises.
2. The six consecutive addresses must be in the order listed. WE must be high during all six consecutive CE controlled cycles to enable a nonvolatile cycle.
3. IO state assumes OE < V . Activation of nonvolatile cycles does not depend on state of OE.
IL
Document Number: 001-51026 Rev. **
Page 6 of 18
STK12C68-5 (SMD5962-94599)
Voltage on DQ or HSB .......................–0.5V to Vcc + 0.5V
Maximum Ratings
0-7
Power Dissipation.......................................................... 1.0W
DC output Current (1 output at a time, 1s duration) .... 15 mA
Exceeding maximum ratings may shorten the useful life of the
device. These user guidelines are not tested.
Storage Temperature ................................. –65°C to +150°C
Temperature under Bias ............................. –55°C to +125°C
Voltage on Input Relative to GND.....................–0.5V to 7.0V
Operating Range
Range
Military
Ambient Temperature
V
CC
-55°C to +125°C
4.5V to 5.5V
Voltage on Input Relative to Vss............–0.6V to V + 0.5V
CC
DC Electrical Characteristics
Over the operating range (V = 4.5V to 5.5V)
CC
Parameter
Description
Average V Current
Test Conditions
Min
Max
Unit
I
t
t
= 35 ns
= 55 ns
75
55
mA
mA
CC1
CC
RC
RC
Dependent on output loading and cycle rate. Values
obtained without output loads.
I
= 0 mA.
OUT
I
I
Average V Current All Inputs Do Not Care, V = Max
3
mA
mA
CC2
CC
CC
during STORE
Average current for duration t
STORE
AverageV Currentat WE > (V – 0.2V). All other inputs cycling.
10
CC3
CC
CC
t
= 200 ns, 5V, 25°C Dependent on output loading and cycle rate. Values
RC
Typical
obtained without output loads.
I
I
Average V
Current All Inputs Do Not Care, V = Max
2
mA
CC4
CAP
CC
during AutoStore Cycle Average current for duration t
STORE
V
Standby Current
t
t
= 35 ns, CE > V
= 55 ns, CE > V
24
19
mA
mA
CC
RC
RC
IH
IH
SB1
(Standby, Cycling TTL
Input Levels)
V
Standby Current CE > (V – 0.2V). All others V < 0.2V or > (V – 0.2V).
2.5
mA
I
CC
CC
IN
CC
SB2
Standby current level after nonvolatile cycle is complete.
Inputs are static. f = 0 MHz.
I
I
Input Leakage Current V = Max, V < V < V
-1
-5
+1
+5
μA
IX
CC
CC
SS
IN
CC
Off State Output
Leakage Current
V
= Max, V < V < V , CE or OE > V or WE < V
IL
μA
OZ
SS
IN
CC
IH
V
V
V
V
V
Input HIGH Voltage
Input LOW Voltage
Output HIGH Voltage
Output LOW Voltage
2.2
V
+ 0.5
CC
V
V
V
V
V
IH
V
– 0.5
SS
0.8
IL
I
I
I
= –4 mA
= 8 mA
= 3 mA
2.4
OH
OL
BL
OUT
OUT
OUT
0.4
0.4
Logic ‘0’ Voltage on
HSB Output
V
Storage Capacitor
Between Vcap pin and Vss, 6V rated. 68 µF +20% nom.
54
260
µF
CAP
Notes
4.
V
reference levels throughout this data sheet refer to VCC if that is where the power supply connection is made, or V
if VCC is connected to ground.
CC
CAP
5. CE > V does not produce standby current levels until any nonvolatile cycle in progress has timed out.
IH
Document Number: 001-51026 Rev. **
Page 7 of 18
STK12C68-5 (SMD5962-94599)
Data Retention and Endurance
Parameter
DATA
Description
Data Retention
Nonvolatile STORE Operations
Min
100
Unit
Years
K
R
NV
1,000
C
Capacitance
In the following table, the capacitance parameters are listed.
Parameter
Description
Input Capacitance
Output Capacitance
Test Conditions
Max
8
Unit
pF
C
C
T = 25°C, f = 1 MHz,
CC
IN
A
V
= 0 to 3.0 V
7
pF
OUT
Thermal Resistance
In the following table, the thermal resistance parameters are listed.
Parameter
Description
Test Conditions
28-CDIP 28-LCC
Unit
ΘJA
Thermal Resistance
(Junction to Ambient)
Test conditions follow standard test methods and
procedures for measuring thermal impedance, per
EIA / JESD51.
TBD
TBD
°C/W
ΘJC
Thermal Resistance
(Junction to Case)
TBD
TBD
°C/W
Figure 7. AC Test Loads
R1 963Ω
R1 963Ω
For Tri-state Specs
5.0V
5.0V
Output
Output
R2
R2
512
30 pF
5 pF
512Ω
Ω
AC Test Conditions
Input Pulse Levels....................................................0V to 3V
Input Rise and Fall Times (10% to 90%)...................... <5 ns
Input and Output Timing Reference Levels.......................1.5
Note
6. These parameters are guaranteed by design and are not tested.
Document Number: 001-51026 Rev. **
Page 8 of 18
STK12C68-5 (SMD5962-94599)
AC Switching Characteristics
SRAM Read Cycle
Parameter
35 ns
55 ns
Description
Unit
Cypress
Alt
Min
Max
Min
Max
Parameter
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
Chip Enable Access Time
Read Cycle Time
35
55
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ACE
ELQV
t
35
55
RC
AA
AVAV, ELEH
[8]
Address Access Time
35
15
55
35
AVQV
Output Enable to Data Valid
Output Hold After Address Change
Chip Enable to Output Active
Chip Disable to Output Inactive
Output Enable to Output Active
Output Disable to Output Inactive
Chip Enable to Power Active
Chip Disable to Power Standby
DOE
OHA
GLQV
5
5
5
5
AXQX
[9]
[9]
LZCE
HZCE
LZOE
HZOE
ELQX
10
10
35
12
12
55
EHQZ
0
0
0
0
GLQX
GHQZ
PU
ELICCH
EHICCL
PD
Switching Waveforms
Figure 8. SRAM Read Cycle 1: Address Controlled
W5&
$''5(66
W$$
W2+$
'4ꢀꢊ'$7$ꢀ287ꢋ
'$7$ꢀ9$/,'
[7]
Figure 9. SRAM Read Cycle 2: CE and OE Controlled
W5&
$''5(66
&(
W$&(
W3'
W+=&(
W/=&(
2(
W+=2(
W'2(
W/=2(
'4ꢀꢊ'$7$ꢀ287ꢋ
'$7$ꢀ9$/,'
$&7,9(
W38
67$1'%<
,&&
Notes
7. WE and HSB must be High during SRAM Read cycles.
8. Device is continuously selected with CE and OE both Low.
9. Measured ±200 mV from steady state output voltage.
Document Number: 001-51026 Rev. **
Page 9 of 18
STK12C68-5 (SMD5962-94599)
SRAM Write Cycle
Parameter
35 ns
55 ns
Description
Write Cycle Time
Unit
Cypress
Alt
Min
Max
Min
Max
Parameter
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
35
25
25
12
0
25
0
0
55
45
45
25
0
45
0
0
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
WC
AVAV
t
Write Pulse Width
PWE
SCE
SD
WLWH, WLEH
t
Chip Enable To End of Write
Data Setup to End of Write
Data Hold After End of Write
Address Setup to End of Write
Address Setup to Start of Write
Address Hold After End of Write
Write Enable to Output Disable
Output Active After End of Write
ELWH, ELEH
t
DVWH, DVEH
t
HD
WHDX, EHDX
t
AW
AVWH, AVEH
t
SA
AVWL, AVEL
t
HA
WHAX, EHAX
[9]
13
15
HZWE
LZWE
WLQZ
WHQX
5
5
Switching Waveforms
Figure 10. SRAM Write Cycle 1: WE Controlled
tWC
ADDRESS
CE
tHA
tSCE
tAW
tSA
tPWE
WE
tHD
tSD
DATA VALID
DATA IN
tHZWE
tLZWE
HIGH IMPEDANCE
PREVIOUS DATA
DATA OUT
Figure 11. SRAM Write Cycle 2: CE Controlled
tWC
ADDRESS
tHA
tSCE
tSA
CE
WE
tAW
tPWE
tSD
tHD
DATA IN
DATA VALID
HIGH IMPEDANCE
DATA OUT
Notes
10. If WE is Low when CE goes Low, the outputs remain in the high impedance state.
11. HSB must be high during SRAM Write cycles.
12.
CE or WE must be greater than V during address transitions.
IH
Document Number: 001-51026 Rev. **
Page 10 of 18
STK12C68-5 (SMD5962-94599)
AutoStore or Power Up RECALL
STK12C68-5
Unit
Parameter
Alt
Description
Min
Max
t
t
t
Power up RECALL Duration
STORE Cycle Duration
550
μs
ms
μs
t
t
t
RESTORE
HLHZ
HRECALL
10
STORE
DELAY
t
Time Allowed to Complete SRAM Cycle
1
HLQZ , BLQZ
V
V
t
Low Voltage Trigger Level
Low Voltage Reset Level
4.0
4.5
3.9
V
V
SWITCH
RESET
V
Rise Time
150
μs
ns
VCCRISE
CC
Low Voltage Trigger (V
) to HSB Low
300
t
SWITCH
VSBL
Switching Waveform
Figure 12. AutoStore/Power Up RECALL
WE
Notes
13. t
starts from the time V rises above V
.
SWITCH
HRECALL
CC
14. CE and OE low for output behavior.
15. CE and OE low and WE high for output behavior.
16. HSB is asserted low for 1us when V
takes place.
drops through V
. If an SRAM Write has not taken place since the last nonvolatile cycle, HSB is released and no store
CAP
SWITCH
Document Number: 001-51026 Rev. **
Page 11 of 18
STK12C68-5 (SMD5962-94599)
Software Controlled STORE/RECALL Cycle
The software controlled STORE/RECALL cycle follows.
35 ns
55 ns
Max
Parameter
Alt
Description
Unit
Min
35
0
Max
Min
55
0
t
t
t
t
t
t
t
t
t
STORE/RECALL Initiation Cycle Time
Address Setup Time
ns
ns
ns
ns
μs
RC
AVAV
AVEL
ELEH
ELAX
SA
Clock Pulse Width
25
20
30
20
CW
Address Hold Time
HACE
RECALL Duration
20
20
RECALL
Switching Waveform
Figure 13. CE Controlled Software STORE/RECALL Cycle
tRC
tRC
ADDRESS # 1
ADDRESS # 6
ADDRESS
tSA
tSCE
CE
tHACE
OE
t
STORE / tRECALL
HIGH IMPEDANCE
DATA VALID
DATA VALID
DQ (DATA)
Notes
17. The software sequence is clocked on the falling edge of CE without involving OE (double clocking aborts the sequence).
18. The six consecutive addresses must be read in the order listed in Table 1 on page 6. WE must be HIGH during all six consecutive cycles.
Document Number: 001-51026 Rev. **
Page 12 of 18
STK12C68-5 (SMD5962-94599)
Hardware STORE Cycle
STK12C68-5
Unit
Parameter
Alt
Description
STORE Cycle Duration
Min
Max
t
t
t
10
ms
ns
t
HLHZ
STORE
t
Hardware STORE High to Inhibit Off
700
t
t
t
RECOVER, HHQX
HLHX
DHSB
PHSB
HLBL
Hardware STORE Pulse Width
15
ns
ns
Hardware STORE Low to STORE Busy
300
Switching Waveform
Figure 14. Hardware STORE Cycle
Note
19. t
is only applicable after t
is complete.
STORE
DHSB
Document Number: 001-51026 Rev. **
Page 13 of 18
STK12C68-5 (SMD5962-94599)
Part Numbering Nomenclature
STK12C68 - 5 C 35 M
Temperature Range:
M - Military (-55 to 125°C)
Speed:
35 - 35 ns
55 - 55 ns
Package:
C = Ceramic 28-pin 300 mil DIP (gold lead finish)
K = Ceramic 28-pin 300 mil DIP (Solder dip finish)
L = Ceramic 28-pin LLC
Retention / Endurance
5 = Military (10 years or 105 cycles)
SMD5962 - 94599 01 MX X
Lead Finish
A = Solder DIP lead finish
C = Gold lead DIP finish
X = Lead finish “A” or “C” is acceptable
Case Outline
X = Ceramic 28-pin 300 mil DIP
Y = Ceramic 28-pin LLC
Device Class Indicator - Class M
Device Type:
01 = 55 ns
03 = 35 ns
Document Number: 001-51026 Rev. **
Page 14 of 18
STK12C68-5 (SMD5962-94599)
Ordering Information
Speed (ns)
Ordering Code
Package Diagram
001-51695
Package Type
28-pin CDIP (300 mil)
28-pin CDIP (300 mil)
28-pin LCC (350 mil)
28-pin CDIP (300 mil)
28-pin CDIP (300 mil)
28-pin LCC (350 mil)
Operating Range
Military
35
STK12C68-5C35M
STK12C68-5K35M
STK12C68-5L35M
STK12C68-5C55M
STK12C68-5K55M
STK12C68-5L55M
001-51695
001-51696
55
001-51695
001-51695
001-51696
The above table contains Final information. Contact your local Cypress sales representative for availability of these parts
Document Number: 001-51026 Rev. **
Page 15 of 18
STK12C68-5 (SMD5962-94599)
Package Diagrams
Figure 15. 28-Pin (300-Mil) Side Braze DIL (001-51695)
001-51695 **
Document Number: 001-51026 Rev. **
Page 16 of 18
STK12C68-5 (SMD5962-94599)
Package Diagrams (continued)
Figure 16. 28-Pad (350-Mil) LCC (001-51696)
1. ALL DIMENSION ARE IN INCHES AND MILLIMETERS [MIN/MAX]
2. JEDEC 95 OUTLINE# MO-041
3. PACKAGE WEIGHT : TBD
001-51696 **
Document Number: 001-51026 Rev. **
Page 17 of 18
STK12C68-5 (SMD5962-94599)
Document History Page
Document Title: STK12C68-5 (SMD5962-94599), 64 Kbit (8K x 8) AutoStore nvSRAM
Document Number: 001-51026
Orig. of
Change
Submission
Date
Rev
ECN No.
Description of Change
**
2666844
GVCH/PYRS
03/02/09
New data sheet
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life support, life saving, critical control or safety applications, unless pursuant to an express written agreement with Cypress. Furthermore, Cypress does not authorize its products for use as critical
components in life-support systems where a malfunction or failure may reasonably be expected to result in significant injury to the user. The inclusion of Cypress products in life-support systems
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United States copyright laws and international treaty provisions. Cypress hereby grants to licensee a personal, non-exclusive, non-transferable license to copy, use, modify, create derivative works of,
and compile the Cypress Source Code and derivative works for the sole purpose of creating custom software and or firmware in support of licensee product to be used only in conjunction with a Cypress
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the express written permission of Cypress.
Disclaimer: CYPRESS MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARD TO THIS MATERIAL, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. Cypress reserves the right to make changes without further notice to the materials described herein. Cypress does not
assume any liability arising out of the application or use of any product or circuit described herein. Cypress does not authorize its products for use as critical components in life-support systems where
a malfunction or failure may reasonably be expected to result in significant injury to the user. The inclusion of Cypress’ product in a life-support systems application implies that the manufacturer
assumes all risk of such use and in doing so indemnifies Cypress against all charges.
Use may be limited by and subject to the applicable Cypress software license agreement.
Document Number: 001-51026 Rev. **
Revised March 02, 2009
Page 18 of 18
AutoStore and QuantumTrap are registered trademarks of Cypress Semiconductor Corporation. All products and company names mentioned in this document may be the trademarks of their respective
holders.
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