STK14CA8
128Kx8 AutoStore nvSRAM
Features
Description
■
25, 35, 45 ns Read Access and Read/Write Cycle Time
The Cypress STK14CA8 is a 1 Mb fast static RAM with a nonvolatile QuantumTrap storage element included with each memory
cell. This SRAM provides fast access and cycle times, ease of
use, and unlimited read and write endurance of a normal SRAM.
■
Unlimited Read/Write Endurance
■
Automatic Nonvolatile STORE on Power Loss
■
Nonvolatile STORE Under Hardware or Software Control
■
Automatic RECALL to SRAM on Power Up
■
Unlimited RECALL Cycles
■
200K STORE Cycles
■
20-Year Nonvolatile Data Retention
■
Single 3.0V + 20%, -10% Operation
■
Commercial and Industrial Temperatures
■
Small Footprint SOIC and SSOP Packages (RoHS Compliant)
es
ig
ns
Data transfers automatically to the nonvolatile storage cells
when power loss is detected (the STORE operation). On power
up, data is automatically restored to the SRAM (the RECALL
operation). Both STORE and RECALL operations are also
available under software control.
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Logic Block Diagram
Quantum Trap
1024 X 1024
d
de
en
VCAP
STORE/
RECALL
CONTROL
RECALL
HSB
m
ec
INPUT BUFFERS
R
ot
N
STORE
STATIC RAM
ARRAY
1024 X 1024
VCC
POWER
CONTROL
om
ROW DECODER
A5
A6
A7
A8
A9
A12
A13
A14
A15
A16
DQ0
DQ1
DQ2
DQ3
DQ4
DQ5
DQ6
DQ7
ew
D
The Cypress nvSRAM is the first monolithic nonvolatile memory
to offer unlimited writes and reads. It is the highest performing
and most reliable nonvolatile memory available.
SOFTWARE
DETECT
A15 – A0
COLUMN I/O
COLUMN DEC
A0 A1 A2 A3 A4 A10 A11
G
E
W
Cypress Semiconductor Corporation
Document Number: 001-51592 Rev. *A
•
198 Champion Court
•
San Jose, CA 95134-1709
•
408-943-2600
Revised December 02, 2009
[+] Feedback
STK14CA8
Contents
SRAM READ ............................................................... 13
SRAM WRITE ............................................................. 13
AutoStore Operation.................................................... 13
Hardware STORE (HSB) Operation............................ 13
Hardware RECALL (Power Up)................................... 13
Software STORE......................................................... 14
Software RECALL ....................................................... 14
Data Protection............................................................ 14
Noise Considerations .................................................. 14
Best Practices ............................................................. 14
Low Average Active Power ......................................... 15
Preventing AutoStore....................................................... 15
STK14CA8-R F 45 ITR ...................................................... 16
Package Diagrams............................................................ 17
Document History Page .................................................... 18
Sales, Solutions, and Legal Information ........................ 18
Worldwide Sales and Design Support......................... 18
Products ...................................................................... 18
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Features............................................................................... 1
Description.......................................................................... 1
Logic Block Diagram.......................................................... 1
Contents .............................................................................. 2
Pinouts ................................................................................ 3
Pin Descriptions ................................................................. 3
Absolute Maximum Ratings .............................................. 4
DC Characteristics ............................................................. 4
Capacitance ........................................................................ 6
SRAM READ Cycles #1 and #2 .................................... 7
SRAM WRITE Cycles #1 and #2................................... 8
AutoStore/POWER UP RECALL ........................................ 9
Software Controlled STORE/RECALL Cycle........... 10
Hardware STORE Cycle ................................................... 11
Soft Sequence Commands ............................................... 11
Mode Selection ................................................................. 12
nvSRAM Operation........................................................... 13
nvSRAM ...................................................................... 13
Document Number: 001-51592 Rev. *A
Page 2 of 17
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STK14CA8
Pinouts
Figure 1. 48-Pin SSOP
Figure 2. 32-Pin SOIC
1
48
VCC
VCAP
1
32
VCC
A16
A14
2
47
A15
A16
2
31
A15
3
46
HSB
30
4
A6
43
5
A5
7
42
6
27
HSB
W
A13
A8
NC
8
41
A4
9
40
A11
A7
A6
A5
A4
29
28
6
W
A13
A8
4
5
45
44
A14
A12
3
A12
A7
NC
10
39
NC
9
NC
11
38
NC
A3
A2
7
8
es
10
NC
12
37
NC
A1
VSS
13
36
VSS
A0
NC
NC
14
35
NC
D
A9
NC
ig
ns
VCAP
15
34
DQ0
16
33
NC
DQ6
A3
17
32
G
A2
18
31
A10
A1
19
30
E
A0
DQ1
DQ2
20
29
DQ7
21
28
DQ5
22
23
27
DQ4
NC
26
DQ3
NC
24
25
VCC
26
25
24
23
A9
A11
G
A10
22
12
21
DQ0
13
20
DQ1
DQ2
14
19
DQ6
DQ5
15
18
DQ4
VSS
16
17
DQ3
E
DQ7
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Figure 3. Relative PCB Area Usage[1]
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Pin Descriptions
Pin Name
I/O
A16-A0
Input
DQ7-DQ0
I/O
E
Input
Chip Enable: The active low E input selects the device.
W
Input
Write Enable: The active low W allows to write the data on the DQ pins to the address location
latched by the falling edge of E.
ec
Address: The 17 address inputs select one of 131,072 bytes in the nvSRAM array.
Data: Bi-directional 8-bit data bus for accessing the nvSRAM.
R
ot
N
G
Description
Input
Output Enable: The active low G input enables the data output buffers during read cycles.
De-asserting G high causes the DQ pins to tri-state.
VCC
Power Supply
Power: 3.0V, +20%, -10%.
HSB
I/O
Hardware Store Busy: When low this output indicates a Store is in progress. When pulled low
external to the chip, it initiates a nonvolatile STORE operation. A weak pull up resistor keeps this
pin high if not connected. (Connection is optional).
VCAP
Power Supply
AutoStore Capacitor: Supplies power to nvSRAM during power loss to store data from SRAM to
nonvolatile storage elements.
VSS
Power Supply
Ground.
NC
No Connect
Unlabeled pins have no internal connections.
Note
1. See Package Diagrams on page 16 for detailed package size specifications.
Document Number: 001-51592 Rev. *A
Page 3 of 17
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STK14CA8
Absolute Maximum Ratings
NF (SOP-32) PACKAGE THERMAL CHARACTERISTICS
θjc 5.4 C/W; θja 44.3 [0fpm], 37.9 [200fpm], 35.1 C/W [500fpm].
Voltage on Input Relative to Ground.................–0.5V to 4.1V
RF (SSOP-48) PACKAGE THERMAL CHARACTERISTICS
Voltage on Input Relative to VSS ...........–0.5V to (VCC + 0.5V)
θjc 6.2 C/W; θja 51.1 [0fpm], 44.7 [200fpm], 41.8 C/W [500fpm].
Voltage on DQ0-7 or HSB ......................–0.5V to (VCC + 0.5V)
Temperature under Bias ............................... –55°C to 125°C
Note: Stresses greater than those listed under Absolute
Maximum Ratings may cause permanent damage to the device.
This is a stress rating only, and functional operation of the device
at conditions above those indicated in the operational sections
of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
reliability.
Junction Temperature ................................... –55°C to 140°C
Storage Temperature .................................... –65°C to 150°C
Power Dissipation............................................................. 1W
ig
ns
DC Output Current (1 output at a time, 1s duration).... 15 mA
es
DC Characteristics
Commercial
Parameter
Min
Industrial
Max
Min
Max
Units
Notes
ew
Symbol
D
(VCC = 2.7V to 3.6V)
mA
mA
mA
tAVAV = 25 ns
tAVAV = 35 ns
tAVAV = 45 ns
Dependent on output loading and cycle
rate. Values obtained without output
loads.
3
mA
All Inputs Don’t Care, VCC = max
Average current for duration of STORE
cycle (tSTORE)
10
mA
W ≥ (V CC – 0.2V)
All Other Inputs Cycling at CMOS Levels
Dependent on output loading and cycle
rate. Values obtained without output
loads.
3
3
mA
All Inputs Don’t Care
Average current for duration of STORE
cycle (tSTORE)
3
3
mA
E ≥ (VCC -0.2V)
All Others VIN≤ 0.2V or ≥ (VCC-0.2V)
Standby current level after nonvolatile
cycle complete
Input Leakage Current
±1
±1
μA
VCC = max
VIN = VSS to VCC
IOLK
Off-State Output Leakage
Current
±1
±1
μA
VCC = max
VIN = VSS to VCC, E or G
ICC2
Average VCC Current during
STORE
3
ICC3
Average VCC Current at tAVAV =
200 ns
3V, 25°C, Typical
ICC4
Average VCAP Current during
AutoStore Cycle
ISB
VCC Standby Current
(Standby, Stable CMOS Levels)
IILK
70
60
55
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65
55
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Average VCC Current
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ICC1
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10
VIH
Input Logic “1” Voltage
2.0
VCC+0.3
2.0
VCC+0.3
V
All Inputs
VIL
Input Logic “0” Voltage
VSS–0.5
0.8
VSS–0.5
0.8
V
All Inputs
V
IOUT = – 2 mA
0.4
V
IOUT = 4 mA
≥ VIH
VOH
Output Logic “1” Voltage
VOL
Output Logic “0” Voltage
TA
Operating Temperature
0
70
–40
85
°C
VCC
Operating Voltage
2.7
3.6
2.7
3.6
V
3.3V + 0.3V
120
17
120
μF
Between VCAP pin and VSS, 5V rated.
2.4
2.4
0.4
VCAP
Storage Capacitance
17
NVC
Nonvolatile STORE operations
200
200
DATAR
Data Retention
20
20
Note
K
Years At 55 °C
The HSB pin has IOUT=-10 uA for VOH of 2.4 V, this parameter is characterized but not tested.
Document Number: 001-51592 Rev. *A
Page 4 of 17
[+] Feedback
STK14CA8
AC Test Conditions
Input Pulse Levels ....................................................0V to 3V
Input Rise and Fall Times ................................................. ≤ 5 ns
Input and Output Timing Reference Levels .................... 1.5V
Output Load..................................See Figure 4 and Figure 5
Capacitance
(TA = 25°C, f = 1.0 MHz)
Input Capacitance
7
pF
COUT
Output Capacitance
7
pF
Conditions
ig
ns
Max Units
CIN
ΔV = 0 to 3V
ΔV = 0 to 3V
3.0V
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577 Ohms
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Figure 4. AC Output Loading
es
Parameter[2]
D
Symbol
OUTPUT
30 pF
INCLUDING
SCOPE AND
FIXTURE
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789 Ohms
m
Figure 5. AC Output Loading for Tristate Specifications
(tHZ, tLZ, tWLQZ, tWHQZ, tGLQX, tGHQZ)
577 Ohms
OUTPUT
789 Ohms
5 pF
INCLUDING
SCOPE AND
FIXTURE
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3.0V
Note
2. These parameters are guaranteed but not tested.
Document Number: 001-51592 Rev. *A
Page 5 of 17
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STK14CA8
SRAM READ Cycles #1 and #2
Symbols
NO.
STK14CA8-25 STK14CA8-35 STK14CA8-45
Parameter
#1
#2
Alt.
Min
Max
Min
Max
tELQV
tACS
Chip Enable Access Time
2
tELEH[3]
tRC
Read Cycle Time
3
tAVQV[4]
tAVQV[4]
tAA
Address Access Time
25
35
45
ns
tGLQV
tOE
Output Enable to Data Valid
12
15
20
ns
tAXQX[4]
tOH
Output Hold after Address Change
3
3
3
ns
6
tELQX
tLZ
Address Change or Chip Enable to
Output Active
3
3
3
ns
7
tEHQZ[5]
tHZ
Address Change or Chip Disable to
Output Inactive
8
tGLQX
tOLZ
Output Enable to Output Active
tGHQZ[5]
tELICCH[2]
tEHICCL[2]
tOHZ
Output Disable to Output Inactive
tPA
Chip Enable to Power Active
tPS
Chip Disable to Power Standby
9
10
11
0
es
13
D
10
0
13
0
15
35
ns
ns
15
0
25
ns
ns
0
10
0
45
45
ig
ns
35
ew
5
tAXQX[4]
25
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4
35
Units
Max
tAVAV[3]
1
25
Min
ns
ns
45
ns
fo
Figure 6. SRAM READ Cycle #1: Address Controlled[3, 4, 6]
d
2
tAVAV
ADDRESS
tAXQX
DATA VALID
m
en
DQ (DATA OUT)
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3
tAVQV
5
2
29
1
11
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Figure 7. SRAM READ Cycle #2: E and G Controlled[3, 6]
7
N
3
4
9
8
10
Notes
3. W must be high during SRAM READ cycles.
4. Device is continuously selected with E and G both low
5. Measured ± 200mV from steady state output voltage.
6. HSB must remain high during READ and WRITE cycles
Document Number: 001-51592 Rev. *A
Page 6 of 17
[+] Feedback
STK14CA8
SRAM WRITE Cycles #1 and #2
NO.
Symbols
#1
#2
STK14CA8-25 STK14CA8-35 STK14CA8-45
Parameter
Alt.
Min
Max
Min
Max
Min
Max
Units
tAVAV
tAVAV
tWC
Write Cycle Time
25
35
45
ns
13
tWLWH
tWLEH
tWP
Write Pulse Width
20
25
30
ns
14
tELWH
tELEH
tCW
Chip Enable to End of Write
20
25
30
ns
15
tDVWH
tDVEH
tDW
Data Setup to End of Write
10
12
15
ns
16
tWHDX
tEHDX
tDH
Data Hold after End of Write
0
0
0
ns
17
tAVWH
tAVEH
tAW
Address Setup to End of Write
20
25
30
ns
18
tAVWL
tAVEL
tAS
Address Setup to Start of Write
0
0
0
ns
19
tWHAX
tEHAX
tWR
Address Hold after End of Write
0
0
ns
20
tWLQZ[5,7]
tWZ
Write Enable to Output Disable
21
tWHQX
tOW Output Active after End of Write
es
0
D
10
3
ew
3
ig
ns
12
13
15
3
ns
ns
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Figure 8. SRAM WRITE Cycle #1: W Controlled[7,8]
12
tAVAV
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ADDRESS
14
tELWH
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E
19
tWHAX
17
tAVWH
18
en
tAVWL
13
tWLWH
15
tDVWH
m
W
DATA VALID
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DATA IN
16
tWHDX
20
tWLQZ
DATA OUT
HIGH IMPEDANCE
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PREVIOUS DATA
21
tWHQX
Figure 9. SRAM WRITE Cycle #2: E Controlled[7,8]
ot
12
tAVAV
N
ADDRESS
18
tAVEL
14
tELEH
19
tEHAX
E
17
tAVEH
W
13
tWLEH
15
tDVEH
DATA IN
DATA OUT
16
tEHDX
DATA VALID
HIGH IMPEDANCE
Notes
7. If W is low when E goes low, the outputs remain in the high impedance state.
8. E or W must be ≥ VIH during address transitions.
Document Number: 001-51592 Rev. *A
Page 7 of 17
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STK14CA8
AutoStore/POWER UP RECALL
NO.
Symbols
STK14CA8
Parameter
Standard Alternate
Min
Units
Notes
20
ms
9
10, 11
Max
22
tHRECALL
Power up RECALL Duration
23
tSTORE
STORE Cycle Duration
12.5
ms
24
VSWITCH
Low Voltage Trigger Level
2.65
V
25
VCCRISE
VCC Rise Time
μs
150
ig
ns
tHLHZ
t
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D
es
Figure 10. AutoStore/POWER UP RECALL
23
23
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m
en
25
22
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22
Note Read and Write cycles are ignored during STORE, RECALL, and while VCC is below VSWITCH.
Notes
9. tHRECALL starts from the time VCC rises above VSWITCH
10. If an SRAM WRITE has not taken place since the last nonvolatile cycle, no STORE takes place
11. Industrial Grade devices require maximum 15 ms.
Document Number: 001-51592 Rev. *A
Page 8 of 17
[+] Feedback
STK14CA8
Software Controlled STORE/RECALL Cycle
NO.
Symbols
E Cont G Cont
STK14CA8-35 STK14CA8-35 STK14CA8-45
Parameter[12,13]
Alt
Min
Max
Min
Max
Min
Max
Units Notes
tAVAV
tAVAV
tRC
STORE/RECALL Initiation Cycle
Time
25
35
45
ns
27
tAVEL
tAVGL
tAS
Address Setup Time
0
0
0
ns
28
tELEH
tGLGH
tCW
Clock Pulse Width
20
25
30
ns
29
tEHAX
tGHAX
Address Hold Time
1
1
1
ns
30
tRECALL tRECALL
RECALL Duration
ig
ns
26
50
50
50
13
μs
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Figure 11. Software STORE/RECALL CYCLE: E Controlled[13]
26
27
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D
26
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28
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29
30
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23
Figure 12. Software STORE/RECALL CYCLE: G Controlled[13]
26
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ec
26
27
28
23
30
29
Notes
12. The software sequence is clocked on the falling edge of E controlled READs or G controlled READs
13. The six consecutive addresses must be read in the order listed in the Software STORE/RECALL Mode Selection Table. W must be high during all six consecutive cycles.
Document Number: 001-51592 Rev. *A
Page 9 of 17
[+] Feedback
STK14CA8
Hardware STORE Cycle
NO.
Symbols
Standard
31
tDELAY
32
tHLHX
tHLQZ
STK14CA8
Parameter
Alternate
Min
Max
Hardware STORE to SRAM Disabled
1
70
Hardware STORE Pulse Width
15
Units
Notes
μs
14
ns
Figure 13. Hardware STORE Cycle
es
ig
ns
32
ew
D
23
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31
STK14CA8
Min
m
Standard
tSS
Soft Sequence Processing Time
Units
Notes
μs
15, 16
Max
70
om
33
Parameter
en
Symbols
NO.
de
Soft Sequence Commands
33
33
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Figure 14. Software Sequence Commands
Notes
14. On a hardware STORE initiation, SRAM operation continues to be enabled for time tDELAY to allow read/write cycles to complete.
15. This is the amount of time that it takes to take action on a soft sequence command. Vcc power must remain high to effectively register command.
16. Commands such as Store and Recall lock out I/O until operation is complete which further increases this time. See specific command.
Document Number: 001-51592 Rev. *A
Page 10 of 17
[+] Feedback
STK14CA8
E
W
G
A16-A0
Mode
I/O
Power
H
X
X
X
Not Selected
Output High Z
Standby
L
H
L
X
Read SRAM
Output Data
Active
L
L
X
X
Write SRAM
Input Data
Active
L
H
L
0x04E38
0x0B1C7
0x083E0
0x07C1F
0x0703F
0x08B45
Read SRAM
Read SRAM
Read SRAM
Read SRAM
Read SRAM
AutoStore Disable
Output Data
Output Data
Output Data
Output Data
Output Data
Output Data
Active
0x04E38
0x0B1C7
0x083E0
0x07C1F
0x0703F
0x04B46
Read SRAM
Read SRAM
Read SRAM
Read SRAM
Read SRAM
AutoStore Enable
Output Data
Output Data
Output Data
Output Data
Output Data
Output Data
D
Mode Selection
0x04E38
0x0B1C7
0x083E0
0x07C1F
0x0703F
Read SRAM
Read SRAM
Read SRAM
Read SRAM
Read SRAM
Output Data
Output Data
Output Data
Output Data
Output Data
Active
0x08FC0
Nonvolatile Store
Output High Z
ICC2
0x04E38
0x0B1C7
0x083E0
0x07C1F
0x0703F
0x04C63
Read SRAM
Read SRAM
Read SRAM
Read SRAM
Read SRAM
Nonvolatile Recall
Output Data
Output Data
Output Data
Output Data
Output Data
Output High Z
Active
ig
ns
es
Active
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17, 18, 19
17, 18, 19
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d
L
de
H
L
17, 18, 19
17, 18, 19
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L
H
L
en
L
H
m
L
Notes
Notes
17. The six consecutive addresses must be in the order listed. W must be high during all six consecutive cycles to enable a nonvolatile cycle.
18. While there are 17 addresses on the STK14CA8, only the lower 16 are used to control software modes
19. I/O state depends on the state of G. The I/O table shown assumes G low
Document Number: 001-51592 Rev. *A
Page 11 of 17
[+] Feedback
STK14CA8
nvSRAM Operation
on page 4 for the size of the capacitor. The voltage on the VCAP
pin is driven to 5V by a charge pump internal to the chip. A pull
up should be placed on W to hold it inactive during power up.
nvSRAM
To reduce unneeded 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. The HSB signal can be monitored by the system to detect
an AutoStore cycle is in progress.
The STK14CA8 nvSRAM has two functional components paired
in the same physical cell. These are the SRAM memory cell and
a nonvolatile QuantumTrap cell. The SRAM memory cell
operates similar to a standard fast static RAM. Data in the SRAM
can be transferred to the nonvolatile cell (the STORE operation),
or from the nonvolatile cell to SRAM (the RECALL operation).
This unique architecture allows all cells to be stored and recalled
in parallel. During the STORE and RECALL operations, SRAM
READ and WRITE operations are inhibited. The STK14CA8
supports unlimited read and writes similar to a typical SRAM. In
addition, it provides unlimited RECALL operations from the
nonvolatile cells and up to 200K STORE operations.
0.1µF
10k Ohm
fo
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W
VCC
d
The STK14CA8 performs a READ cycle whenever E and G are
low while W and HSB are high. The address specified on pins
A0-16 determine which of the 131,072 data bytes are accessed.
When the READ is initiated by an address transition, the outputs
are valid after a delay of tAVQV (READ cycle #1). If the READ is
initiated by E and G, the outputs are valid at tELQV or at tGLQV,
whichever is later (READ cycle #2). The data outputs repeatedly
responds to address changes within the tAVQV access time
without the need for transitions on any control input pins, and
remains valid until another address change or until E or G is
brought high, or W and HSB is brought low.
D
SRAM READ
VCC
es
VCAP
VCAP
ig
ns
Figure 15. AutoStore Mode
de
SRAM WRITE
om
m
en
A WRITE cycle is performed whenever E and W are low and HSB
is high. The address inputs must be stable prior to entering the
WRITE cycle and must remain stable until either E or W goes
high at the end of the cycle. The data on the common I/O pins
DQ0-7 are written into memory if it is valid tDVWH before the end
of a W controlled WRITE or tDVEH before the end of an E
controlled WRITE.
R
ec
It is recommended that G be kept high during the entire WRITE
cycle to avoid data bus contention on common I/O lines. If G is
left low, internal circuitry turns off the output buffers tWLQZ after
W goes low.
AutoStore Operation
N
ot
The STK14CA8 stores data to nvSRAM using one of three
storage operations. These three operations are Hardware Store
(activated by HSB), Software Store (activated by an address
sequence), and AutoStore (on power down).
AutoStore operation is a unique feature of Cypress Quantum
Trap technology is enabled by default on the STK14CA8.
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.
Figure 15 shows the proper connection of the storage capacitor
(VCAP) for automatic store operation. Refer to DC Characteristics
Document Number: 001-51592 Rev. *A
Hardware STORE (HSB) Operation
The STK14CA8 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 STK14CA8 conditionally initiates a STORE operation
after tDELAY. An actual STORE cycle only begins if a WRITE to
the SRAM took place since the last STORE or RECALL cycle.
The HSB pin has a very resistive pull up and is internally driven
low to indicate a busy condition while the STORE (initiated by
any means) is in progress. This pin should be externally pulled
up if it is used to drive other inputs.
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
STK14CA8 continues to allow SRAM operations for tDELAY.
During tDELAY, multiple SRAM READ operations may take place.
If a WRITE is in progress when HSB is pulled low, it is allowed a
time tDELAY to complete. However, any SRAM WRITE cycles
requested after HSB goes low are inhibited until HSB returns
high.
If HSB is not used, it should be left unconnected.
Hardware RECALL (Power Up)
During power up or after any low power condition
(VCC