Catalyst CAT24C44PATE13 256-bit serial nonvolatile cmos static ram Datasheet

CAT24C44
256-Bit Serial Nonvolatile CMOS Static RAM
FEATURES
■ Single 5V Supply
■ JEDEC Standard Pinouts:
–8-pin DIP
–8-pin SOIC
■ Infinite E2PROM to RAM Recall
■ CMOS and TTL Compatible I/O
■ 100,000 Program/Erase Cycles (E2PROM)
■ Low CMOS Power Consumption:
■ Auto Recall on Power-up
–Active: 3 mA Max.
–Standby: 30 µA Max.
■ Commercial, Industrial and Automotive
Temperature Ranges
■ Power Up/Down Protection
■ 10 Year Data Retention
DESCRIPTION
The CAT24C44 Serial NVRAM is a 256-bit nonvolatile
memory organized as 16 words x 16 bits. The high
speed Static RAM array is bit for bit backed up by a
nonvolatile E2PROM array which allows for easy transfer of data from RAM array to E2PROM (STORE) and
from E2PROM to RAM (RECALL). STORE operations
are completed in 10ms max. and RECALL operations
typically within 1.5µs. The CAT24C44 features unlimited
RAM write operations either through external RAM
writes or internal recalls from E2PROM. Internal false
store protection circuitry prohibits STORE operations
when VCC is less than 3.5V (typical) ensuring E2PROM
data integrity.
PIN CONFIGURATION
PIN FUNCTIONS
The CAT24C44 is manufactured using Catalyst’s advanced CMOS floating gate technology. It is designed to
endure 100,000 program/erase cycles (E2PROM) and
has a data retention of 10 years. The device is available
in JEDEC approved 8-pin plastic DIP and SOIC packages.
Pin Name
DIP Package (P)
CE
SK
DI
DO
1
2
3
4
8
7
6
5
VCC
STORE
RECALL
VSS
SOIC Package (S)
CE
SK
DI
DO
1
2
3
4
8
7
6
5
VCC
STORE
RECALL
VSS
5157 FHD F01
© 1998 by Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
Function
SK
Serial Clock
DI
Serial Input
DO
Serial Data Output
CE
Chip Enable
RECALL
Recall
STORE
Store
VCC
+5V
VSS
Ground
Doc. No. 25019-0A 2/98 N-1
1
CAT24C44
BLOCK DIAGRAM
E2PROM ARRAY
RECALL
ROW
DECODE
STATIC RAM
ARRAY
256-BIT
STORE
STORE
CONTROL
LOGIC
RECALL
CE
INSTRUCTION
REGISTER
DI
COLUMN
DECODE
DO
SK
VCC
VSS
INSTRUCTION
DECODE
4-BIT
COUNTER
5157 FHD F09
MODE SELECTION(1)(2)
Mode
STORE
RECALL
Software
Instruction
Write Enable
Latch
Previous Recall
Latch
Hardware Recall(3)
1
0
NOP
X
X
Software Recall
1
1
RCL
X
X
Hardware Store(3)
0
1
NOP
SET
TRUE
Software Store
1
1
STO
SET
TRUE
X = Don’t Care
POWER-UP TIMING(4)
Symbol
Parameter
Min.
Max.
Units
VCCSR
VCC Slew Rate
0.5
0.005
V/m
tpur
Power-Up to Read Operations
200
µs
tpuw
Power-Up to Write or Store Operation
5
ms
Note:
(1) The store operation has priority over all the other operations.
(2) The store operation is inhibited when VCC is below ≈ 3.5V.
(3) NOP designates that the device is not currently executing an instruction.
(4) This parameter is tested initially and after a design or process change that affects the parameter.
Doc. No. 25019-0A 2/98 N-1
2
CAT24C44
ABSOLUTE MAXIMUM RATINGS*
*COMMENT
Temperature Under Bias ................. –55°C to +125°C
Stresses above those listed under “Absolute Maximum
Ratings” may cause permanent damage to the device.
These are stress ratings only, and functional operation
of the device at these or any other conditions outside of
those listed in the operational sections of this specification is not implied. Exposure to any absolute maximum
rating for extended periods may affect device performance and reliability.
Storage Temperature ....................... –65°C to +150°C
Voltage on Any Pin with
Respect to Ground(2) ............. –2.0 to +VCC +2.0V
VCC with Respect to Ground ............... –2.0V to +7.0V
Package Power Dissipation
Capability (Ta = 25°C) ................................... 1.0W
Lead Soldering Temperature (10 secs) ............ 300°C
Output Short Circuit Current(3) ........................ 100 mA
RELIABILITY CHARACTERISTICS
Symbol
Parameter
Min.
Max.
Units
Reference Test Method
100,000
Cycles/Byte
MIL-STD-883, Test Method 1033
10
Years
MIL-STD-883, Test Method 1008
MIL-STD-883, Test Method 3015
NEND(1)
Endurance
TDR(1)
Data Retention
VZAP(1)
ESD Susceptibility
2000
Volts
ILTH(1)(4)
Latch-Up
100
mA
JEDEC Standard 17
D.C. OPERATING CHARACTERISTICS
VCC = 5V ±10%, unless otherwise specified.
Limits
Symbol
Parameter
ICCO
Min.
Typ.
Max.
Unit
Conditions
Current Consumption (Operating)
3
mA
Inputs = 5.5V, TA = 0°C
All Outputs Unloaded
ISB
Current Consumption (Standby)
30
µA
CE = VIL
ILI
Input Current
2
µA
0 ≤ VIN ≤ 5.5V
ILO
Output Leakage Current
10
µA
0 ≤ VOUT ≤ 5.5V
VIH
High Level Input Voltage
2
VCC
V
VIL
Low Level Input Voltage
0
0.8
V
VOH
High Level Output Voltage
VOL
Low Level Output Voltage
2.4
0.4
V
IOH = –2mA
V
IOL = 4.2mA
CAPACITANCE TA = 25°C, f = 1.0 MHz, VCC = 5V
Symbol
CI/O(1)
CIN(1)
Parameter
Max.
Unit
Conditions
Input/Output Capacitance
10
pF
VI/O = 0V
Input Capacitance
6
pF
VIN = 0V
Note:
(1) This parameter is tested initially and after a design or process change that affects the parameter.
(2) The minimum DC input voltage is –0.5V. During transitions, inputs may undershoot to –2.0V for periods of less than 20 ns.
Maximum DC voltage on output pins is VCC +0.5V, which may overshoot to VCC +2.0V for periods of less than 20 ns.
(3) Output shorted for no more than one second. No more than one output shorted at a time.
(4) Latch-up protection is provided for stresses up to 100 mA on address and data pins from –1V to VCC +1V.
3
Doc. No. 25019-0A 2/98 N-1
CAT24C44
A.C. CHARACTERISTICS
VCC = 5V ±10%, unless otherwise specified.
Symbol
Parameter
Min.
Max.
Units
1
MHz
Conditions
FSK
SK Frequency
DC
tSKH
SK Positive Pulse Width
400
ns
tSKL
SK Negative Pulse Width
400
ns
CL = 100pF + 1TTL gate
tDS
Data Setup Time
400
ns
VOH = 2.2V, VOL = 0.65V
tDH
Data Hold Time
80
ns
VIH = 2.2V, VIL = 0.65V
tPD
SK Data Valid Time
375
ns
Input rise and fall times = 10ns
tZ
CE Disable Time
1
µs
tCES
CE Enable Setup Time
800
ns
tCEH
CE Enable Hold Time
400
ns
tCDS
CE De-Select Time
800
ns
A.C. CHARACTERISTICS, Store Cycle
VCC = 5V ±10%, unless otherwise specified.
Limits
Symbol
Parameter
tST
Store Time
tSTP
Store Pulse Width
tSTZ
Store Disable Time
Min.
Max.
Units
Conditions
10
ms
CL = 100pF + 1TTL gate
ns
VOH = 2.2V, VOL = 0.65V
100
ns
VIH = 2.2V, VIL = 0.65V
Max.
Units
Conditions
200
A.C. CHARACTERISTICS, Recall Cycle
VCC = 5V ±10%, unless otherwise specified.
Symbol
Parameter
Min.
tRCC
Recall Cycle Time
2.5
µs
tRCP
Recall Pulse Width
500
ns
CL = 100pF + 1TTL gate
tRCZ
Recall Disable Time
ns
VOH = 2.2V, VOL = 0.65V
tORC
Recall Enable Time
ns
VIH = 2.2V, VIL = 0.65V
tARC
Recall Data Access Time
500
10
1.5
µs
INSTRUCTION SET
Format
Instruction
Start Bit
Address
OP Code
Operation
WRDS
1
XXXX
000
Reset Write Enable Latch (Disables, Writes and Stores)
STO
1
XXXX
001
Store RAM Data in E2PROM
WRITE
1
AAAA
011
Write Data into RAM Address AAAA
WREN
1
XXXX
100
Set Write Enable Latch (Enables, Writes and Stores)
RCL
1
XXXX
101
Recall E2PROM Data into RAM
READ
1
AAAA
11X
Read Data From RAM Address AAAA
X = Don’t care
A = Address bit
Doc. No. 25019-0A 2/98 N-1
4
CAT24C44
from the device: If the CE pin is prematurely deselected
while shifting in an instruction, that instruction will not be
executed, and the shift register internal to the CAT24C44
will be cleared. If there are more than or less than 16
clocks during a memory data transfer, an improper data
transfer will result. The SK clock is completely static
allowing the user to stop the clock and restart it to
resume shifting of data.
DEVICE OPERATION
The CAT24C44 is intended for use with standard microprocessors. The CAT24C44 is organized as 16 registers
by 16 bits. Seven 8-bit instructions control the device’s
operating modes, the RAM reading and writing, and the
E2PROM storing and recalling. It is also possible to
control the E2PROM store and recall functions in hardware with the STORE and RECALL pins. The CAT24C44
operates on a single 5V supply and will generate, on
chip, the high voltage required during a RAM to E2PROM
storing operation.
Read
Upon receiving a start bit, 4 address bits, and the 3-bit
read command (clocked into the DI pin), the DO pin of
the CAT24C44 will come out of the high impedance state
and the 16 bits of data, located at the address specified
in the instructions, will be clocked out of the device.
When clocking data from the device, the first bit clocked
out (DO) is timed from the falling edge of the 8th clock,
all succeeding bits (D1–D15) are timed from the rising
edge of the clock.
Instructions, addresses and write data are clocked into
the DI pin on the rising edge of the clock (SK). The DO
pin remains in a high impedance state except when
outputting data from the device. The CE (Chip Enable)
pin must remain high during the entire data transfer.
The format for all instructions sent to the CAT24C44 is
a logical ‘1’ start bit, 4 address bits (data read or write
operations) or 4 “Don’t Care” bits (device mode operations), and a 3-bit op code (see Instruction Set). For data
write operations, the 8-bit instruction is followed by 16
bits of data. For data read instructions, DO will come out
of the high impedance state and enable 16 bits of data
to be clocked from the device. The 8th bit of the read
instruction is a “Don’t Care” bit. This is to eliminate any
bus contention that would occur in applications where
the DI and DO pins are tied together to form a common
DI/DO line. A word of caution while clocking data to and
Write
After receiving a start bit, 4 address bits, and the 3-bit
WRITE command, the 16-bit word is clocked into the
device for storage into the RAM memory location specified. The CE pin must remain high during the entire write
operation.
Figure 1. RAM Read Cycle Timing
CE
1
2
3
4
5
6
7
8
1
A
A
A
A
1
1
X
9
10
11
12
22
23
24
SK
(8)
(1)
DI
HIGH-Z
DO
D0
D1
D2
D3
D14
D15
D0
5157 FHD F02
Figure 2. RAM Write Cycle Timing
CE
1
2
3
4
5
6
7
1
A
A
A
A
0
1
8
9
10
11
12
22
23
24
SK
DI
1
Note:
(1) Bit 8 of READ instruction is “Don’t Care”.
D0
D1
D2
D3
D13
D14
D15
5157 FHD F03
5
Doc. No. 25019-0A 2/98 N-1
CAT24C44
WREN/WRDS
(STO). The WRDS (write/store disable) can be used to
disable all CAT24C44 programming functions, and will
prevent any accidental writing to the RAM, or storing to
the E2PROM.
The CAT24C44 powers up in the program disable state
(the “write enable latch” is reset). Any programming
after power-up or after a WRDS (RAM write/E2PROM
store disable) instruction must first be preceded by the
WREN (RAM write/E2PROM store enable) instruction.
Once writing/storing is enabled, it will remain enabled
until power to the device is removed, the WRDS instruction is sent, or an E2PROM store has been executed
Data can be read normally from the CAT24C44 regardless of the “write enable latch” status.
Figure 3. Read Cycle Timing
SK CYCLE #
6
7
8
9
10
11
SK
V IH
CE
t PD
DI
t PD
tZ
HIGH-Z
DO
D0
D1
Dn
HIGH-Z
5157 FHD F04
Figure 4. Write Cycle Timing
1/F SK
t SKH
SK
x
t SKL
1
2
n
t CES
t CEH
t CDS
CE
t DS
t DH
DI
5157 FHD F05
Doc. No. 25019-0A 2/98 N-1
6
CAT24C44
RECALL
RCL/RECALL
inadvertent store operations, the following conditions
must each be met before data can be transferred into
nonvolatile storage:
Data is transferred from the E2PROM data memory to
RAM by either sending the RCL instruction or by pulling
the RECALL input pin low. A recall operation must be
performed before the E2PROM store, or RAM write
operations can be executed. Either a hardware or software recall operation will set the “previous recall” latch
internal to the CAT24C44.
• The “previous recall” latch must be set (either a
software or hardware recall operation).
• The “write enable” latch must be set (WREN
instruction issued).
POWER-ON RECALL
• STO instruction issued or STORE input low.
The CAT24C44 has a power-on recall function that
transfers the E2PROM data to the RAM. After Power-up,
all functions are inhibited for at least 200ns (Tpur) from
stable Vcc.
During the store operation, all other CAT24C44 functions are inhibited. Upon completion of the store operation, the “write enable” latch is reset. The device also
provides false store protection whenever VCC falls below
a 3.5V level. If VCC falls below this level, the store
operation is disabled and the “write enable” latch is
reset.
STORE
STO/STORE
Data in the RAM memory area is stored in the E2PROM
memory either by sending the STO instruction or by
pulling the STORE input pin low. As security against any
Figure 5. Recall Cycle Timing
tRCC
tRCP
RECALL
tRCZ
tARC
HIGH-Z
DO
VALID DATA
tORC
UNDEFINED DATA
5157 FHD F06
Figure 6. Hardware Store Cycle Timing
tST
tSTP
STORE
tSTZ
HIGH-Z
DO
5157 FHD F07
7
Doc. No. 25019-0A 2/98 N-1
CAT24C44
Figure 7. Non-Data Operations
CE
1
2
3
4
5
1
X
X
X
X
6
7
8
SK
DI
OP-CODE
5157 FHD F08
ORDERING INFORMATION
Prefix
Device #
CAT
24C44
Optional
Company ID
Product
Number
Suffix
S
I
-TE13
Temperature Range
Blank = Commercial (0˚ - 70˚C)
I = Industrial (-40˚ - 85˚C)
A = Automotive (-40˚ - 105˚C)*
Tape & Reel
TE13: 2000/Reel
Package
P: PDIP
S: SOIC (JEDEC)
24C44 F11
* -40˚ to +125˚C is available upon request
Notes:
(1) The device used in the above example is a 24C44SI-TE13 (SOIC, Industrial Temperature, Tape & Reel)
Doc. No. 25019-0A 2/98 N-1
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