Catalyst CAT28C256P-15T 32k-bit parallel e2prom Datasheet

CAT28C256
32K-Bit Parallel E2PROM
FEATURES
■ Fast Read Access Times: 120/150ns
■ Hardware and Software Write Protection
■ Low Power CMOS Dissipation:
■ Automatic Page Write Operation:
–1 to 64 Bytes in 5ms
–Page Load Timer
–Active: 25 mA Max.
–Standby: 150 µA Max.
■ End of Write Detection:
■ Simple Write Operation:
–Toggle Bit
–DATA Polling
–On-Chip Address and Data Latches
–Self-Timed Write Cycle with Auto-Clear
■ 100,000 Program/Erase Cycles
■ Fast Write Cycle Time:
–5ms Max
■ 100 Year Data Retention
■ CMOS and TTL Compatible I/O
■ Commerical, Industrial and Automotive
Temperature Ranges
DESCRIPTION
The CAT28C256 is a fast, low power, 5V-only CMOS
parallel E2PROM organized as 32K x 8-bits. It requires a
simple interface for in-system programming. On-chip
address and data latches, self-timed write cycle with autoclear and VCC power up/down write protection eliminate
additional timing and protection hardware. DATA Polling
and Toggle status bits signal the start and end of the selftimed write cycle. Additionally, the CAT28C256 features
hardware and software write protection.
The CAT28C256 is manufactured using Catalyst’s advanced CMOS floating gate technology. It is designed to
endure 100,000 program/erase cycles and has a data
retention of 100 years. The device is available in JEDEC
approved 28-pin DIP, 28-pin TSOP or 32-pin PLCC
packages.
BLOCK DIAGRAM
A6–A14
ADDR. BUFFER
& LATCHES
ROW
DECODER
VCC
INADVERTENT
WRITE
PROTECTION
HIGH VOLTAGE
GENERATOR
CE
OE
WE
CONTROL
LOGIC
64 BYTE PAGE
REGISTER
I/O BUFFERS
TIMER
A0–A5
32,768 x 8
E2PROM
ARRAY
DATA POLLING
AND
TOGGLE BIT
ADDR. BUFFER
& LATCHES
I/O0–I/O7
COLUMN
DECODER
5096 FHD F02
© 1998 by Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
1
Doc. No. 25020-0A 2/98
CAT28C256
PIN CONFIGURATION
VCC
WE
A13
A8
A9
A11
OE
16
15
I/O4
I/O3
A10
CE
I/O7
I/O6
I/O5
A14
NC
VCC
WE
A13
28
27
26
25
24
23
22
21
20
19
18
17
4 3 2 1 32 31 30
A6
A5
A4
A3
5
6
7
8
A2
A1
A0
NC
9
25
10
24
11
23
12
22
13
21
14 15 16 17 18 19 20
I/O0
29
28
27
26
A8
A9
A11
NC
OE
A10
CE
I/O7
I/O6
VSS
NC
I/O3
I/O4
I/O5
1
2
3
4
5
6
7
8
9
10
11
12
13
14
I/O1
I/O2
A14
A12
A7
A6
A5
A4
A3
A2
A1
A0
I/O0
I/O1
I/O2
VSS
PLCC Package (N)
A7
A12
DIP Package (P)
5096 FHD F01
TSOP Package (8mm X 13.4mm) (T13)
OE
A11
A9
A8
A13
WE
VCC
A14
A12
A7
A6
A5
A4
A3
28
27
26
25
24
23
22
21
20
19
18
17
16
15
1
2
3
4
5
6
7
8
9
10
11
12
13
14
A10
CE
I/O7
I/O6
I/O5
I/O4
I/O3
GND
I/O2
I/O1
I/O0
A0
A1
A2
28C256 F03
PIN FUNCTIONS
Pin Name
Function
Pin Name
Function
A0–A14
Address Inputs
WE
Write Enable
I/O0–I/O7
Data Inputs/Outputs
VCC
5V Supply
CE
Chip Enable
VSS
Ground
OE
Output Enable
NC
No Connect
Doc. No. 25020-0A 2/98
2
CAT28C256
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) ........... –2.0V 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
Test Method
104 or 105
Cycles/Byte
MIL-STD-883, Test Method 1033
NEND(1)
Endurance
TDR(1)
Data Retention
100
Years
MIL-STD-883, Test Method 1008
VZAP(1)
ESD Susceptibility
2000
Volts
MIL-STD-883, Test Method 3015
ILTH(1)(4)
Latch-Up
100
mA
JEDEC Standard 17
D.C. OPERATING CHARACTERISTICS
VCC = 5V ±10%, unless otherwise specified.
Limits
Symbol
Parameter
Min.
Typ.
Max.
Units
Test Conditions
ICC
VCC Current (Operating, TTL)
30
mA
CE = OE = VIL, f=8MHz
All I/O’s Open
ICCC(5)
VCC Current (Operating, CMOS)
25
mA
CE = OE = VILC, f=8MHz
All I/O’s Open
ISB
VCC Current (Standby, TTL)
1
mA
CE = VIH, All I/O’s Open
ISBC(6)
VCC Current (Standby, CMOS)
150
µA
CE = VIHC,
All I/O’s Open
ILI
Input Leakage Current
–10
10
µA
VIN = GND to VCC
ILO
Output Leakage Current
–10
10
µA
VOUT = GND to VCC,
CE = VIH
VIH(6)
High Level Input Voltage
2
VCC +0.3
V
VIL(5)
Low Level Input Voltage
–0.3
0.8
V
VOH
High Level Output Voltage
2.4
VOL
Low Level Output Voltage
VWI
Write Inhibit Voltage
0.4
3.5
V
IOH = –400µA
V
IOL = 2.1mA
V
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 100mA on address and data pins from –1V to VCC +1V.
(5) VILC = –0.3V to +0.3V.
(6) VIHC = VCC –0.3V to VCC +0.3V.
3
Doc. No. 25020-0A 2/98
CAT28C256
MODE SELECTION
Mode
CE
WE
OE
Read
L
H
Byte Write (WE Controlled)
L
Byte Write (CE Controlled)
I/O
Power
L
DOUT
ACTIVE
H
DIN
ACTIVE
L
H
DIN
ACTIVE
Standby, and Write Inhibit
H
X
X
High-Z
STANDBY
Read and Write Inhibit
X
H
H
High-Z
ACTIVE
CAPACITANCE TA = 25°C, f = 1.0 MHz, VCC = 5V
Symbol
Test
Max.
Units
Conditions
CI/O(1)
Input/Output Capacitance
10
pF
VI/O = 0V
CIN(1)
Input Capacitance
6
pF
VIN = 0V
A.C. CHARACTERISTICS, Read Cycle
VCC=5V + 10%, Unless otherwise specified
Parameter
28C256-12
Min. Max.
28C256-15
Min. Max.
Units
tRC
Read Cycle Time
120
150
ns
tCE
CE Access Time
120
150
ns
tAA
Address Access Time
120
150
ns
tOE
OE Access Time
50
70
ns
Symbol
tLZ(1)
tOLZ
(1)
tHZ(1)(2)
tOHZ
(1)(2)
tOH(1)
CE Low to Active Output
0
0
ns
OE Low to Active Output
0
0
ns
CE High to High-Z Output
50
50
ns
OE High to High-Z Output
50
50
ns
Output Hold from Address Change
0
0
ns
Note:
(1) This parameter is tested initially and after a design or process change that affects the parameter.
(2) Output floating (High-Z) is defined as the state when the external data line is no longer driven by the output buffer.
Doc. No. 25020-0A 2/98
4
CAT28C256
A.C. CHARACTERISTICS, Write Cycle
VCC=5V+10%, unless otherwise specified
28C256-12
Min. Max.
28C256-15
Min. Max.
Symbol
Parameter
tWC
Write Cycle Time
tAS
Address Setup Time
0
0
ns
tAH
Address Hold Time
50
50
ns
tCS
CE Setup Time
0
0
ns
tCH
CE Hold Time
0
0
ns
tCW(3)
CE Pulse Time
100
100
ns
tOES
OE Setup Time
0
0
ns
tOEH
OE Hold Time
0
0
ns
tWP(3)
WE Pulse Width
100
100
ns
tDS
Data Setup Time
50
50
ns
tDH
Data Hold Time
10
10
ns
tINIT(1)
Write Inhibit Period After Power-up
5
10
5
10
ms
0.1
100
0.1
100
µs
tBLC(1)(4)
5
Byte Load Cycle Time
5
Units
ms
Figure 1. A.C. Testing Input/Output Waveform(2)
2.4 V
2.0 V
INPUT PULSE LEVELS
REFERENCE POINTS
0.8 V
0.45 V
5096 FHD F03
Figure 2. A.C. Testing Load Circuit (example)
1.3V
1N914
3.3K
DEVICE
UNDER
TEST
OUT
CL = 100 pF
5096 FHD F04
CL INCLUDES JIG CAPACITANCE
Note:
(1) This parameter is tested initially and after a design or process change that affects the parameter.
(2) Input rise and fall times (10% and 90%) < 10 ns.
(3) A write pulse of less than 20ns duration will not initiate a write cycle.
(4) A timer of duration tBLC max. begins with every LOW to HIGH transition of WE. If allowed to time out, a page or byte write will begin;
however a transition from HIGH to LOW within tBLC max. stops the timer.
5
Doc. No. 25020-0A 2/98
CAT28C256
Byte Write
DEVICE OPERATION
A write cycle is executed when both CE and WE are low,
and OE is high. Write cycles can be initiated using either
WE or CE, with the address input being latched on the
falling edge of WE or CE, whichever occurs last. Data,
conversely, is latched on the rising edge of WE or CE,
whichever occurs first. Once initiated, a byte write cycle
automatically erases the addressed byte and the new
data is written within 5 ms.
Read
Data stored in the CAT28C256 is transferred to the data
bus when WE is held high, and both OE and CE are
held low. The data bus is set to a high impedance state
when either CE or OE goes high. This 2-line control
architecture can be used to eliminate bus contention in
a system environment.
Figure 3. Read Cycle
tRC
ADDRESS
tCE
CE
tOE
OE
VIH
tLZ
WE
tOHZ
DATA OUT
tHZ
tOH
tOLZ
HIGH-Z
DATA VALID
DATA VALID
tAA
28C256 F06
Figure 4. Byte Write Cycle [WE Controlled]
tWC
ADDRESS
tAS
tAH
tCH
tCS
CE
OE
tOES
tWP
tOEH
WE
tBLC
DATA OUT
DATA IN
HIGH-Z
DATA VALID
tDS
tDH
5096 FHD F06
Doc. No. 25020-0A 2/98
6
CAT28C256
Page Write
(which can be loaded in any order) during the first and
subsequent write cycles. Each successive byte load
cycle must begin within tBLC MAX of the rising edge of the
preceding WE pulse. There is no page write window
limitation as long as WE is pulsed low within tBLC MAX.
The page write mode of the CAT28C256 (essentially an
extended BYTE WRITE mode) allows from 1 to 64 bytes
of data to be programmed within a single E2PROM write
cycle. This effectively reduces the byte-write time by a
factor of 64.
Upon completion of the page write sequence, WE must
stay high a minimum of tBLC MAX for the internal automatic program cycle to commence. This programming
cycle consists of an erase cycle, which erases any data
that existed in each addressed cell, and a write cycle,
which writes new data back into the cell. A page write will
only write data to the locations that were addressed and
will not rewrite the entire page.
Following an initial WRITE operation (WE pulsed low, for
tWP, and then high) the page write mode can begin by
issuing sequential WE pulses, which load the address
and data bytes into a 64 byte temporary buffer. The page
address where data is to be written, specified by bits A6
to A14, is latched on the last falling edge of WE. Each
byte within the page is defined by address bits A0 to A5
Figure 5. Byte Write Cycle [CE Controlled]
tWC
ADDRESS
tAS
tAH
tBLC
tCW
CE
tOEH
OE
tCS
tOES
tCH
WE
HIGH-Z
DATA OUT
DATA IN
DATA VALID
tDS
tDH
5096 FHD F07
Figure 6. Page Mode Write Cycle
OE
CE
t WP
t BLC
WE
ADDRESS
t WC
I/O
LAST BYTE
BYTE 0
BYTE 1
BYTE 2
BYTE n
BYTE n+1
BYTE n+2
5096 FHD F10
7
Doc. No. 25020-0A 2/98
CAT28C256
DATA Polling
Toggle Bit
DATA polling is provided to indicate the completion of
write cycle. Once a byte write or page write cycle is
initiated, attempting to read the last byte written will
output the complement of that data on I/O7 (I/O0–I/O6
are indeterminate) until the programming cycle is complete. Upon completion of the self-timed write cycle, all
I/O’s will output true data during a read cycle.
In addition to the DATA Polling feature of the CAT28C256,
the device offers an additional method for determining
the completion of a write cycle. While a write cycle is in
progress, reading data from the device will result in I/O6
toggling between one and zero. However, once the write
is complete, I/O6 stops toggling and valid data can be
read from the device.
Figure 7. DATA Polling
ADDRESS
CE
WE
tOEH
tOES
tOE
OE
tWC
I/O7
DIN = X
DOUT = X
DOUT = X
28C256 F10
Figure 8. Toggle Bit
WE
CE
tOEH
tOES
tOE
OE
I/O6
(1)
(1)
tWC
28C256 F11
Note:
(1) Beginning and ending state of I/O6 is indeterminate.
Doc. No. 25020-0A 2/98
8
CAT28C256
HARDWARE DATA PROTECTION
The following is a list of hardware data protection features that are incorporated into the CAT28C256.
(4) Noise pulses of less than 20 ns on the WE or CE
inputs will not result in a write cycle.
(1) VCC sense provides for write protection when VCC
falls below 3.5V min.
SOFTWARE DATA PROTECTION
The CAT28C256 features a software controlled data
protection scheme which, once enabled, requires a data
algorithm to be issued to the device before a write can be
performed. The device is shipped from Catalyst with the
software protection NOT ENABLED (the CAT28C256 is
in the standard operating mode).
(2) A power on delay mechanism, tINIT (see AC characteristics), provides a 5 to 10 ms delay before a write
sequence, after VCC has reached 3.5V min.
(3) Write inhibit is activated by holding any one of OE
low, CE high or WE high.
Figure 9. Write Sequence for Activating Software
Data Protection
WRITE DATA:
ADDRESS:
WRITE DATA:
ADDRESS:
WRITE DATA:
ADDRESS:
Figure 10. Write Sequence for Deactivating
Software Data Protection
WRITE DATA:
AA
ADDRESS:
5555
WRITE DATA:
55
ADDRESS:
2AAA
WRITE DATA:
A0
ADDRESS:
5555
WRITE DATA:
SOFTWARE DATA
(12)
(1)
PROTECTION ACTIVATED
ADDRESS:
XX
WRITE DATA:
TO ANY ADDRESS
ADDRESS:
WRITE LAST BYTE
TO
LAST ADDRESS
WRITE DATA:
WRITE DATA:
ADDRESS:
5096 FHD F08
AA
5555
55
2AAA
80
5555
AA
5555
55
2AAA
20
5555
5096 FHD F09
Note:
(1) Write protection is activated at this point whether or not any more writes are completed. Writing to addresses must occur within tBLC
Max., after SDP activation.
9
Doc. No. 25020-0A 2/98
CAT28C256
To activate the software data protection, the device must
be sent three write commands to specific addresses with
specific data (Figure 9). This sequence of commands
(along with subsequent writes) must adhere to the page
write timing specifications (Figure 11). Once this is done,
all subsequent byte or page writes to the device must be
preceded by this same set of write commands. The data
protection mechanism is activated until a deactivate
sequence is issued regardless of power on/off transitions. This gives the user added inadvertent write protection on power-up in addition to the hardware protection provided.
To allow the user the ability to program the device with
an E2PROM programmer (or for testing purposes) there
is a software command sequence for deactivating the
data protection. The six step algorithm (Figure 10) will
reset the internal protection circuitry, and the device will
return to standard operating mode (Figure 12 provides
reset timing). After the sixth byte of this reset sequence
has been issued, standard byte or page writing can
commence.
Figure 11. Software Data Protection Timing
DATA
ADDRESS
AA
5555
55
2AAA
tWC
A0
5555
BYTE OR
PAGE
WRITES
ENABLED
CE
tWP
tBLC
WE
5096 FHD F13
Figure 12. Resetting Software Data Protection Timing
DATA
ADDRESS
AA
5555
55
2AAA
80
5555
AA
5555
55
2AAA
20
5555
tWC
SDP
RESET
CE
DEVICE
UNPROTECTED
WE
5096 FHD F14
ORDERING INFORMATION
Prefix
Device #
CAT
28C256
Suffix
H
Product
Number
Optional
Company
ID
Endurance
Blank = 10,000 Cycle
H = 100,000 Cycle
N
I
-15
Temperature Range
Blank = Commercial (0˚C to +70˚C)
I = Industrial (-40˚C to +85˚C)
A = Automotive (-40˚ to +105˚C)*
Package
P: PDIP
N: PLCC
T13: TSOP (8mmx13.4mm)
* -40˚C to +125˚C is available upon request
T
Tape & Reel
T: 500/Reel
Speed
12: 120ns
15: 150ns
28C256 F16
Notes:
(1) The device used in the above example is a CAT28C256HNI-15T (100,000 Cycle Endurance, PLCC, Industrial temperature, 150ns
Access Time, Tape & Reel).
Doc. No. 25020-0A 2/98
10
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