STK12C68
64 Kbit (8K x 8) AutoStore nvSRAM
Features
Functional Description
■
25 ns, 35 ns, and 45 ns access times
The Cypress STK12C68 is a fast static RAM with a nonvolatile
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
Commercial and industrial temperatures
228-pin (330mil) SOIC, 28-pin (300mil) PDIP, 28-pin (600mil)
PDIP packages
■
■
28-pin (300 mil) CDIP and 28-pad (350 mil) LCC packages
RoHS compliance
Logic Block Diagram
V
CC
V
CAP
Quantum Trap
128 X 512
A5
A6
POWER
CONTROL
STORE
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
DQ6
DQ7
A0
A4
A10
A1
A3
A2
OE
CE
WE
Cypress Semiconductor Corporation
Document Number: 001-51027 Rev. **
•
198 Champion Court
•
San Jose, CA 95134-1709
•
408-943-2600
Revised January 30, 2009
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STK12C68
During normal operation, the device draws current from VCC to
charge a capacitor connected to the VCAP pin. This stored
charge is used by the chip to perform a single STORE operation.
If the voltage on the VCC pin drops below VSWITCH, the part
automatically disconnects the VCAP pin from VCC. A STORE
operation is initiated with power provided by the VCAP capacitor.
Device Operation
The STK12C68 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 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.
Figure 2 shows the proper connection of the storage capacitor
(VCAP) for automatic store operation. A charge storage capacitor
between 68 µF and 220 µF (+20%) rated at 6V should be
provided. The voltage on the VCAP pin is driven to 5V by a charge
pump internal to the chip. A pull up is placed on WE to hold it
inactive during power up.
Figure 2. AutoStore Mode
SRAM Read
The STK12C68 performs a Read cycle whenever CE and OE are
LOW while WE and HSB are HIGH. The address specified on
pins A0–12 determines the 8,192 data bytes accessed. When the
Read is initiated by an address transition, the outputs are valid
after a delay of tAA (Read cycle 1). If the Read is initiated by CE
or OE, the outputs are valid at tACE or at tDOE, whichever is later
(Read cycle 2). The data outputs repeatedly respond to address
changes within the tAA access time without the need for transi-
tions 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.
9&$3
9FF
:(
+6%
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 DQ0–7 are written into the memory if it has valid tSD, before
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 tHZWE after WE goes
LOW.
9VV
In system power mode, both VCC and VCAP are connected to the
+5V power supply without the 68 μF capacitor. In this mode, the
AutoStore function of the STK12C68 operates on the stored
system charge as power goes down. The user must, however,
guarantee that VCC does not drop below 3.6V during the 10 ms
STORE cycle.
AutoStore Operation
The STK12C68 stores data to nvSRAM using one of three
storage operations:
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.
Document Number: 001-51027 Rev. **
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STK12C68
Figure 3. AutoStore Inhibit Mode
During any STORE operation, regardless of how it is initiated,
the STK12C68 continues to drive the HSB pin LOW, releasing it
only when the STORE is complete. After completing the STORE
operation, the STK12C68 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 (VCC
<
V
RESET), an internal RECALL request is latched. When VCC
once again exceeds the sense voltage of VSWITCH, a RECALL
cycle is automatically initiated and takes tHRECALL to complete.
If the STK12C68 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 VCC or between CE and system VCC
.
Software STORE
Data is transferred from the SRAM to the nonvolatile memory by
a software address sequence. The STK12C68 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 VSWITCH, then a 2.2 ohm resistor should be connected
between VCC and the system supply to avoid momentary excess
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.
of current between VCC and VCAP
.
AutoStore Inhibit Mode
If an automatic STORE on power loss is not required, then VCC
disabled. If the STK12C68 is operated in this configuration, refer-
ences to VCC are changed to VCAP throughout this data sheet.
In this mode, STORE operations are triggered through software
control or the HSB pin. To enable or disable Autostore using an
to change between these three options “on the fly”.
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
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 is LOW for
a valid sequence. After the tSTORE cycle time is fulfilled, the
SRAM is again activated for Read and Write operation.
The STK12C68 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 conditionally initiates a STORE operation
after tDELAY. An actual STORE cycle only begins if a 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 continues SRAM operations for tDELAY. During
tDELAY, multiple SRAM Read operations take place. If a Write is
in progress when HSB is pulled LOW, it allows a time, tDELAY 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
Document Number: 001-51027 Rev. **
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STK12C68
3. Read address 0x0AAA, Valid READ
4. Read address 0x1FFF, Valid READ
5. Read address 0x10F0, Valid READ
6. Read address 0x0F0E, Initiate RECALL cycle
■
■
The VCC level
IO loading
Figure 4. 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 tRECALL cycle time, the SRAM is again
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 protects data from corruption during low voltage
conditions by inhibiting all externally initiated STORE and Write
operations. The low voltage condition is detected when VCC is
less than VSWITCH. If the STK12C68 is in a Write 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 5. Current Versus Cycle Time (Write)
Noise Considerations
The STK12C68 is a high speed memory. It must have a high
frequency bypass capacitor of approximately 0.1 µF connected
between VCC and VSS, using leads and traces that are as short
as possible. As with all high speed CMOS ICs, careful routing of
power, ground, and signals reduce circuit noise.
Hardware Protect
The STK12C68 offers hardware protection against inadvertent
STORE operation and SRAM Writes during low voltage condi-
tions. When VCAP<VSWITCH, all externally initiated STORE
operations and SRAM Writes are inhibited. AutoStore can be
completely disabled by tying VCC to ground and applying +5V to
V
CAP. 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.
Preventing Store
Low Average Active Power
The STORE function is disabled by holding HSB high with a
driver capable of sourcing 30 mA at a VOH of at least 2.2V,
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 is connected for AutoStore operation
CMOS technology provides the STK12C68 the benefit of
drawing significantly less current when it is cycled at times longer
shown for both CMOS and TTL input levels (commercial temper-
ature 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 depends on the
following items:
(system VCC connected to VCC and a 68 μF capacitor on VCAP
)
and VCC crosses VSWITCH on the way down, the STK12C68
attempts to pull HSB LOW. If HSB does not actually get below
VIL, the part stops trying to pull HSB LOW and abort the STORE
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
Document Number: 001-51027 Rev. **
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STK12C68
manufacturing test to ensure these system routines work
consistently.
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 applications has
resulted in the following suggestions as best practices:
■
Power up boot firmware routines should 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).
■
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.
Theendproduct’sfirmwareshouldnotassumethatanNVarray
is in a set programmed state. Routines that check memory
content values to determine first time system configuration,
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
■
The Vcap value specified in this data sheet includesa minimum
and a maximum value size. The best practice is to meet this
requirementandnotexceedthemaximumVcapvaluebecause
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 should
discuss their Vcap size selection with Cypress.
Table 1. Hardware Mode Selection
CE
H
L
WE
X
HSB
H
A12–A0
Mode
IO
Power
Standby
Active
X
X
X
X
Not Selected
Read SRAM
Write SRAM
Output High Z
Output Data
Input Data
H
H
L
L
H
X
X
L
Nonvolatile STORE Output High Z
ICC2
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 ICC2
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
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. I/O state assumes OE < V . Activation of nonvolatile cycles does not depend on state of OE.
IL
Document Number: 001-51027 Rev. **
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STK12C68
Voltage on DQ0-7 or HSB .......................–0.5V to Vcc + 0.5V
Power Dissipation.......................................................... 1.0W
DC output Current (1 output at a time, 1s duration) .... 15 mA
Maximum Ratings
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
Voltage on Input Relative to Vss............–0.6V to VCC + 0.5V
Operating Range
Range
Commercial
Industrial
Ambient Temperature
0°C to +70°C
VCC
4.5V to 5.5V
4.5V to 5.5V
-40°C to +85°C
DC Electrical Characteristics
Parameter
Description
Test Conditions
Min
Max
Unit
ICC1
Average VCC Current tRC = 25 ns
85
75
65
mA
mA
mA
t
RC = 35 ns
tRC = 45 ns
Dependent on output loading and cycle rate. Values obtained
without output loads.
I
OUT = 0 mA.
Average VCC Current All Inputs Do Not Care, VCC = Max
during STORE Average current for duration tSTORE
Average VCC Current at WE > (VCC – 0.2V). All other inputs cycling.
RC= 200 ns, 5V, 25°C Dependent on output loading and cycle rate. Values obtained
Typical without output loads.
ICC2
ICC3
3
mA
mA
10
t
ICC4
Average VCAP Current All Inputs Do Not Care, VCC = Max
during AutoStore Cycle Average current for duration tSTORE
2
mA
[5]
ISB1
VCC Standby Current
(Standby, Cycling TTL tRC = 35 ns, CE > VIH
Input Levels)
tRC = 25 ns, CE > VIH
27
24
20
mA
mA
mA
tRC = 45 ns, CE > VIH
[5]
ISB2
VCC Standby Current
CE > (VCC – 0.2V). All others VIN < 0.2V or > Commercial
(VCC – 0.2V). Standby current level after
1.5
mA
nonvolatile cycle is complete.
Inputs are static. f = 0 MHz.
Industrial
2.5
mA
IIX
Input Leakage Current VCC = Max, VSS < VIN < VCC
Input Leakage Current VCC = Max, VSS < VIN < VCC
-1
-1
-5
+1
+1
+5
μA
μA
μA
IIX
IOZ
Off State Output
Leakage Current
VCC = Max, VSS < VIN < VCC, CE or OE > VIH or WE < VIL
VIH
Input HIGH Voltage
2.2
VCC
0.5
+
V
VIL
Input LOW Voltage
VSS – 0.5
2.4
0.8
V
V
V
V
VOH
VOL
VBL
Output HIGH Voltage IOUT = –4 mA
Output LOW Voltage
IOUT = 8 mA
OUT = 3 mA
0.4
0.4
Logic ‘0’ Voltage on
HSB Output
I
VCAP
Storage Capacitor
Between Vcap pin and Vss, 6V rated. 68 µF +20% nom.
54
260
µF
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: 001-51027 Rev. **
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STK12C68
Data Retention and Endurance
Parameter
DATAR
Description
Data Retention
Nonvolatile STORE Operations
Min
100
Unit
Years
K
NVC
1,000
Capacitance
Parameter
CIN
Description
Input Capacitance
Output Capacitance
Test Conditions
Max
8
Unit
pF
TA = 25°C, f = 1 MHz,
CC = 0 to 3.0 V
V
COUT
7
pF
Thermal Resistance
In the following table, the thermal resistance parameters are listed.[6]
28-PDIP 28-PDIP
(300 mil) (600 mil)
Parameter
Description
Test Conditions
28-SOIC
28-CDIP
28-LCC
Unit
ΘJA
Thermal Resis-
tance
(Junction to
Ambient)
Test conditions follow
standard test methods and
procedures for measuring
thermal impedance, per EIA /
JESD51.
46.55
45.16
55.84
46.1
95.31
°C/W
ΘJC
Thermal Resis-
tance
27.95
31.62
25.74
5.01
9.01
°C/W
(Junction to Case)
Figure 6. 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..................................................0 V to 3 V
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: 001-51027 Rev. **
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STK12C68
AC Switching Characteristics
SRAM Read Cycle
Parameter
25 ns
35 ns
45 ns
Unit
Description
Cypress
Alt
Min
Max
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
25
35
45
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ACE
ELQV
t
25
35
45
RC
AA
AVAV, ELEH
[8]
Address Access Time
25
10
35
15
45
20
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
[8]
5
5
5
5
5
5
AXQX
[9]
[9]
[9]
[9]
LZCE
HZCE
LZOE
HZOE
ELQX
10
10
25
10
10
35
12
12
45
EHQZ
0
0
0
0
0
0
GLQX
GHQZ
[6]
PU
ELICCH
EHICCL
[6]
PD
Switching Waveforms
W5&
$''5(66
W$$
W2+$
'4ꢀꢊ'$7$ꢀ287ꢋ
'$7$ꢀ9$/,'
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: 001-51027 Rev. **
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STK12C68
SRAM Write Cycle
Parameter
25 ns
35 ns
45 ns
Unit
Description
Write Cycle Time
Cypress
Parameter
Alt
Min
Max
Min
Max
Min
Max
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
25
20
20
10
0
35
25
25
12
0
45
30
30
15
0
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
WC
AVAV
WLWH, WLEH
t
Write Pulse Width
PWE
SCE
SD
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
20
0
25
0
30
0
AW
AVWH, AVEH
t
SA
AVWL, AVEL
t
0
0
0
HA
WHAX, EHAX
10
13
14
HZWE
LZWE
WLQZ
WHQX
5
5
5
Switching Waveforms
tWC
ADDRESS
CE
tHA
tSCE
tAW
tSA
tPWE
WE
tHD
tSD
DATA VALID
DATA IN
tHZWE
tLZWE
HIGH IMPEDANCE
PREVIOUS DATA
DATA OUT
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: 001-51027 Rev. **
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STK12C68
AutoStore or Power Up RECALL
STK12C68
Max
Parameter
Alt
Description
Unit
Min
[13]
t
t
t
t
t
t
Power up RECALL Duration
STORE Cycle Duration
550
10
μs
ms
HRECALL
RESTORE
HLHZ
STORE
DELAY
t
Time Allowed to Complete SRAM Cycle
Low Voltage Trigger Level
Low Voltage Reset Level
1
μs
V
HLQZ , BLQZ
V
V
t
4.0
4.5
3.9
SWITCH
RESET
V
V
Rise Time
150
μs
ns
VCCRISE
CC
t
Low Voltage Trigger (V
) to HSB Low
300
VSBL
SWITCH
Switching Waveform
Figure 11. 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: 001-51027 Rev. **
Page 11 of 20
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STK12C68
Software Controlled STORE/RECALL Cycle
The software controlled STORE/RECALL cycle follows.
25 ns
35 ns
45 ns
Unit
Parameter
Alt
Description
Min
Max
Min
Max
Min
Max
RC
t
t
t
t
t
t
t
t
t
STORE/RECALL Initiation Cycle Time
Address Setup Time
25
0
35
0
45
0
ns
ns
ns
ns
AVAV
AVEL
ELEH
ELAX
[17]
SA
CW
Clock Pulse Width
20
20
25
20
30
20
[17]
Address Hold Time
HACE
RECALL Duration
20
20
20
μs
RECALL
Switching Waveform
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: 001-51027 Rev. **
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STK12C68
Hardware STORE Cycle
STK12C68
Parameter
Alt
Description
STORE Cycle Duration
Unit
Min
Max
10
t
t
t
t
t
t
t
ms
ns
ns
ns
STORE
HLHZ
t
Hardware STORE High to Inhibit Off
Hardware STORE Pulse Width
700
DHSB
PHSB
HLBL
RECOVER, HHQX
15
HLHX
Hardware STORE Low to STORE Busy
300
Switching Waveform
Figure 13. Hardware STORE Cycle
Note
19. t
is only applicable after t
is complete.
STORE
DHSB
Document Number: 001-51027 Rev. **
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STK12C68
Part Numbering nomenclature
STK12C68 - S F 45 I TR
Packaging Option:
TR = Tape and Reel
Blank = Tube
Temperature Range:
C - Commercial (0 to 70°C)
I - Industrial (-40 to 85°C)
Speed:
25 - 25 ns
35 - 35 ns
45 - 45 ns
Lead Finish
F = 100% Sn (Matte Tin)
Package:
S = Plastic 28-pin 330 mil SOIC
P = Plastic 28-pin 300 mil DIP
W = Plastic 28-pin 600 mil DIP
C = Ceramic 28-pin 300 mil DIP
L = Ceramic 28-pin LLC
Ordering Information
Speed (ns)
Ordering Code
STK12C68-SF25TR
STK12C68-SF25
STK12C68-PF25
STK12C68-WF25
STK12C68-SF25ITR
STK12C68-SF25I
STK12C68-PF25I
STK12C68-WF25I
STK12C68-C35
Package Diagram
001-85058
001-85058
001-85014
001-85017
001-85058
001-85058
001-85014
001-85017
001-51695
001-51696
001-51695
001-51696
Package Type
28-pin SOIC (330 mil)
28-pin SOIC (330 mil)
28-pin PDIP (300 mil)
28-pin PDIP (600 mil)
28-pin SOIC (330 mil)
28-pin SOIC (330 mil)
28-pin PDIP (300 mil)
28-pin PDIP (600 mil)
28-pin CDIP (300 mil)
28-pin LCC (350 mil)
28-pin CDIP (300 mil)
28-pin LCC (350 mil)
Operating Range
Commercial
25
Industrial
35
Commercial
Industrial
STK12C68-L35
STK12C68-C35I
STK12C68-L35I
Document Number: 001-51027 Rev. **
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STK12C68
Ordering Information (continued)
Speed (ns)
Ordering Code
STK12C68-SF45TR
STK12C68-SF45
STK12C68-PF45
STK12C68-WF45
STK12C68-C45
Package Diagram
001-85058
001-85058
001-85014
001-85017
001-51695
001-51696
001-85058
001-85058
001-85014
001-85017
001-51695
001-51696
Package Type
28-pin SOIC (330 mil)
28-pin SOIC (330 mil)
28-pin PDIP (300 mil)
28-pin PDIP (600 mil)
28-pin CDIP (300 mil)
28-pin LCC (350 mil)
28-pin SOIC (330 mil)
28-pin SOIC (330 mil)
28-pin PDIP (300 mil)
28-pin PDIP (600 mil)
28-pin CDIP (300 mil)
28-pin LCC (350 mil)
Operating Range
Commercial
45
STK12C68-L45
STK12C68-SF45ITR
STK12C68-SF45I
STK12C68-PF45I
STK12C68-WF45I
STK12C68-C45I
STK12C68-L45I
Industrial
All parts are Pb-free. The above table contains Final information. Contact your local Cypress sales representative for availability of these parts
Document Number: 001-51027 Rev. **
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STK12C68
Package Diagrams
Figure 14. 28-Pin (330 Mil) SOIC (51-85058)
51-85058 *A
Figure 15. 28-Pin (300 Mil) PDIP (51-85014)
51-85014 *D
Document Number: 001-51027 Rev. **
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STK12C68
Package Diagrams (continued)
Figure 16. 28-Pin (600 Mil) PDIP (51-85017)
51-85017 *B
Document Number: 001-51027 Rev. **
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STK12C68
Package Diagrams (continued)
Figure 17. 28-Pin (300 Mil) Side Braze DIL (001-51695)
001-51695 **
Document Number: 001-51027 Rev. **
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STK12C68
Package Diagrams (continued)
Figure 18. 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: 001-51027 Rev. **
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STK12C68
Document History Page
Document Title: STK12C68 64 Kbit (8K x 8) AutoStore nvSRAM
Document Number: 001-51027
Orig. of
Change
Submission
Date
Rev.
ECN No.
Description of Change
**
2606744
GVCH
01/30/2009 New data sheet
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© Cypress Semiconductor Corporation, 2006-2009. The information contained herein is subject to change without notice. Cypress Semiconductor Corporation assumes no responsibility for the use of
any circuitry other than circuitry embodied in a Cypress product. Nor does it convey or imply any license under patent or other rights. Cypress products are not warranted nor intended to be used for
medical, 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,
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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: 001-51027 Rev. **
Revised January 30, 2009
Page 20 of 20
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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