NV25256WF
256-Kb SPI Serial
Automotive EEPROM in
Wettable Flank Package
Description
The NV25256 is a 256−Kb Serial CMOS EEPROM device
internally organized as 32Kx8 bits. This features a 64−byte page write
buffer and supports the Serial Peripheral Interface (SPI) protocol. The
device is enabled through a Chip Select (CS) input. In addition, the
required bus signals are clock input (SCK), data input (SI) and data
output (SO) lines. The HOLD input may be used to pause any serial
communication with the NV25256 device. The device features
software and hardware write protection, including partial as well as
full array protection.
On−Chip ECC (Error Correction Code) makes the device suitable
for high reliability applications.
Features
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1
UDFN8
(Wettable Flank)
MUW3 SUFFIX
CASE 517DH
PIN CONFIGURATIONS
CS
SO
WP
V
SS
1
V
CC
HOLD
SCK
SI
UDFN8 (MUW3)
(Top View)
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•
•
•
•
•
•
•
•
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Automotive Temperature Grade 1 (−40°C to +125°C)
10 MHz (5 V) SPI Compatible
1.8 V to 5.5 V Supply Voltage Range
SPI Modes (0,0) & (1,1)
64−byte Page Write Buffer
Additional Identification Page with Permanent Write Protection
Self−timed Write Cycle
Hardware and Software Protection
Block Write Protection
− Protect 1/4, 1/2 or Entire EEPROM Array
Low Power CMOS Technology
1,000,000 Program/Erase Cycles
100 Year Data Retention
8−pad Wettable Flank UDFN 2x3 mm Package
This Device is Pb−Free, Halogen Free/BFR Free, and RoHS
Compliant
V
CC
PIN FUNCTION
Pin Name
CS
SO
WP
V
SS
SI
SCK
HOLD
V
CC
Function
Chip Select
Serial Data Output
Write Protect
Ground
Serial Data Input
Serial Clock
Hold Transmission Input
Power Supply
SI
CS
WP
HOLD
SCK
NV25256WF
SO
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 12 of this data sheet.
V
SS
Figure 1. Functional Symbol
©
Semiconductor Components Industries, LLC, 2017
1
January, 2018 − Rev. 1
Publication Order Number:
NV25256/D
NV25256WF
DEVICE MARKING
(UDFN8)
S8W
AWLYWG
G
S8W= Specific Device Code
A
= Assembly Location
WL = Wafer Lot Number
YW = Assembly Start Week
G
= Pb−Free Package
(Note: Microdot may be in either location)
Table 1. ABSOLUTE MAXIMUM RATINGS
Parameters
Operating Temperature
Storage Temperature
Voltage on any Pin with Respect to Ground (Note 1)
Ratings
−45 to +130
−65 to +150
−0.5 to +6.5
Units
°C
°C
V
Stresses exceeding those listed in the Maximum Ratings table may damage the device. If any of these limits are exceeded, device functionality
should not be assumed, damage may occur and reliability may be affected.
1. The DC input voltage on any pin should not be lower than −0.5 V or higher than V
CC
+ 0.5 V. During transitions, the voltage on any pin may
undershoot to no less than −1.5 V or overshoot to no more than V
CC
+ 1.5 V, for periods of less than 20 ns.
Table 2. RELIABILITY CHARACTERISTICS
(Note 2)
Symbol
N
END
(Notes 3, 4)
T
DR
Endurance
Data Retention
Parameter
Min
1,000,000
100
Units
Program / Erase Cycles
Years
2. These parameters are tested initially and after a design or process change that affects the parameter according to appropriate AEC−Q100
and JEDEC test methods.
3. Page Mode, V
CC
= 5 V, 25°C.
4. The device uses ECC (Error Correction Code) logic with 6 ECC bits to correct one bit error in 4 data bytes. Therefore, when a single byte
has to be written, 4 bytes (including the ECC bits) are re-programmed. It is recommended to write by multiple of 4 bytes in order to benefit
from the maximum number of write cycles.
Table 3. D.C. OPERATING CHARACTERISTICS
(
V
CC
= 1.8 V to 5.5 V, T
A
= −40°C to +125°C, unless otherwise specified.)
Symbol
I
CCR
I
CCW
I
SB1
I
SB2
I
L
I
LO
V
IL
V
IH
V
OL
V
OH
Parameter
Supply Current (Read Mode)
Supply Current (Write Mode)
Standby Current
Standby Current
Input Leakage Current
Output Leakage Current
Input Low Voltage
Input High Voltage
Output Low Voltage
Output High Voltage
I
OL
= 3.0 mA
I
OH
= −1.6 mA
V
CC
− 0.8 V
Test Conditions
Read, SO open, f
SCK
= 10 MHz
Write, CS = V
CC
V
IN
= GND or V
CC
, CS = V
CC
,
WP = V
CC
, V
CC
= 5.5 V
V
IN
= GND or V
CC
, CS = V
CC
,
WP = GND, V
CC
= 5.5 V
V
IN
= GND or V
CC
CS = V
CC
V
OUT
= GND or V
CC
−2
−2
−0.5
0.7 V
CC
Min
Max
2
2
3
5
2
2
0.3 V
CC
V
CC
+ 0.5
0.4
Units
mA
mA
mA
mA
mA
mA
V
V
V
V
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NV25256WF
Table 4. PIN CAPACITANCE
(Note 5) (T
A
= 25°C, f = 1.0 MHz, V
CC
= +5.0 V)
Symbol
C
OUT
C
IN
Output Capacitance (SO)
Input Capacitance (CS, SCK, SI, WP, HOLD)
Test
Conditions
V
OUT
= 0 V
V
IN
= 0 V
Min
Typ
Max
8
8
Units
pF
pF
5. These parameters are tested initially and after a design or process change that affects the parameter according to appropriate AEC−Q100
and JEDEC test methods.
Table 5. A.C. CHARACTERISTICS
(V
CC
= 1.8 V to 5.5 V, T
A
= −40°C to +125°C, unless otherwise specified.) (Note 6)
VCC = 1.8 V to 5.5 V
Symbol
f
SCK
t
SU
t
H
t
WH
t
WL
t
LZ
t
RI
(Note 7)
t
FI
(Note 7)
t
HD
t
CD
t
V
t
HO
t
DIS
t
HZ
t
CS
t
CSS
t
CSH
t
CNS
t
CNH
t
WPS
t
WPH
t
WC
(Note 8)
Clock Frequency
Data Setup Time
Data Hold Time
SCK High Time
SCK Low Time
HOLD to Output Low Z
Input Rise Time
Input Fall Time
HOLD Setup Time
HOLD Hold Time
Output Valid from Clock Low
Output Hold Time
Output Disable Time
HOLD to Output High Z
CS High Time
CS Setup Time
CS Hold Time
CS Inactive Setup Time
CS Inactive Hold Time
WP Setup Time
WP Hold Time
Write Cycle Time
80
60
60
60
60
10
10
5
0
50
100
40
30
30
20
20
10
10
5
0
10
80
0
20
25
Parameter
Min
DC
20
20
75
75
50
2
2
0
10
40
Max
5
VCC = 2.5 V to 5.5 V
Min
DC
10
10
40
40
25
2
2
Max
10
Units
MHz
ns
ns
ns
ns
ns
ms
ms
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ms
6. AC Test Conditions:
Input Pulse Voltages: 0.3 V
CC
to 0.7 V
CC
at V
CC
= 2.5 V − 5.5 V and 0.25 V
CC
to 0.75 V V
CC
= 1.8 V − 2.5 V.
Input rise and fall times:
≤
10 ns
Input and output reference voltages: 0.5 V
CC
Output load: current source I
OL max
/I
OH max
; C
L
= 30 pF
7. This parameter is tested initially and after a design or process change that affects the parameter.
8. t
WC
is the time from the rising edge of CS after a valid write sequence to the end of the internal write cycle.
Table 6. POWER−UP TIMING
(Notes 7, 9)
Symbol
t
PUR
t
PUW
Parameter
Power−up to Read Operation
Power−up to Write Operation
Min
0.1
0.1
Max
1
1
Units
ms
ms
9. t
PUR
and t
PUW
are the delays required from the time V
CC
is stable until the specified operation can be initiated.
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NV25256WF
Pin Description
Functional Description
SI:
The serial data input pin accepts op−codes, addresses
and data. In SPI modes (0,0) and (1,1) input data is latched
on the rising edge of the SCK clock input.
SO:
The serial data output pin is used to transfer data out of
the device. In SPI modes (0,0) and (1,1) data is shifted out
on the falling edge of the SCK clock.
SCK:
The serial clock input pin accepts the clock provided
by the host and used for synchronizing communication
between host and NV25256.
CS:
The chip select input pin is used to enable/disable the
NV25256. When CS is high, the SO output is tri−stated (high
impedance) and the device is in Standby Mode (unless an
internal write operation is in progress).
Every communication
session between host and NV25256 must be preceded by a
high to low transition and concluded with a low to high
transition of the CS input.
WP:
The write protect input pin will allow all write
operations to the device when held high. When WP pin is
tied low and the WPEN bit in the Status Register (refer to
Status Register description, later in this Data Sheet) is set to
“1”, writing to the Status Register is disabled.
HOLD:
The HOLD input pin is used to pause transmission
between host and NV25256, without having to retransmit
the entire sequence at a later time. To pause, HOLD must be
taken low and to resume it must be taken back high, with the
SCK input low during both transitions. When not used for
pausing, it is recommended the HOLD input to be tied to
V
CC
, either directly or through a resistor.
The NV25256 device supports the Serial Peripheral
Interface (SPI) bus protocol, modes (0,0) and (1,1). The
device contains an 8−bit instruction register. The instruction
set and associated op−codes are listed in Table 7.
Reading data stored in the NV25256 is accomplished by
simply providing the READ command and an address.
Writing to the NV25256, in addition to a WRITE command,
address and data, also requires enabling the device for
writing by first setting certain bits in a Status Register, as will
be explained later.
After a high to low transition on the CS input pin, the
NV25256 will accept any one of the six instruction op−codes
listed in Table 7 and will ignore all other possible 8−bit
combinations. The communication protocol follows the
timing from Figure 2.
The NV25256 features an additional Identification Page
(64 bytes) which can be accessed for Read and Write
operations when the IPL bit from the Status Register is set
to “1”. The user can also choose to make the Identification
Page permanent write protected.
Table 7. INSTRUCTION SET
Instruction
WREN
WRDI
RDSR
WRSR
READ
WRITE
Opcode
0000 0110
0000 0100
0000 0101
0000 0001
0000 0011
0000 0010
t
CS
Operation
Enable Write Operations
Disable Write Operations
Read Status Register
Write Status Register
Read Data from Memory
Write Data to Memory
CS
t
CSS
t
WH
t
WL
t
CNH
SCK
t
CSH
t
CNS
t
SU
SI
t
H
VALID
IN
t
V
t
RI
t
FI
t
V
t
HO
VALID
OUT
t
DIS
HI−Z
HI−Z
SO
Figure 2. Synchronous Data Timing
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NV25256WF
Status Register
The Status Register, as shown in Table 8, contains a
number of status and control bits.
The RDY (Ready) bit indicates whether the device is busy
with a write operation. This bit is automatically set to 1 during
an internal write cycle, and reset to 0 when the device is ready
to accept commands. For the host, this bit is read only.
The WEL (Write Enable Latch) bit is set/reset by the
WREN/WRDI commands. When set to 1, the device is in a
Write Enable state and when set to 0, the device is in a Write
Disable state.
The BP0 and BP1 (Block Protect) bits determine which
blocks are currently write protected. They are set by the user
with the WRSR command and are non−volatile. The user is
allowed to protect a quarter, one half or the entire memory,
by setting these bits according to Table 9. The protected
blocks then become read−only.
The WPEN (Write Protect Enable) bit acts as an enable for
the WP pin. Hardware write protection is enabled when the
WP pin is low and the WPEN bit is 1. This condition
prevents writing to the status register and to the block
Table 8. STATUS REGISTER
7
WPEN
6
IPL
5
0
4
LIP
protected sections of memory. While hardware write
protection is active, only the non−block protected memory
can be written. Hardware write protection is disabled when
the WP pin is high or the WPEN bit is 0. The WPEN bit, WP
pin and WEL bit combine to either permit or inhibit Write
operations, as detailed in Table 10.
The IPL (Identification Page Latch) bit determines
whether the additional Identification Page (IPL = 1) or main
memory array (IPL = 0) can be accessed both for Read and
Write operations. The IPL bit is set by the user with the
WRSR command and is volatile. The IPL bit is
automatically reset after read/write operations.
The LIP bit is set by the user with the WRSR command
and is non−volatile. When set to 1, the Identification Page is
permanently write protected (locked in Read−only mode).
Note: The IPL and LIP bits cannot be set to 1 using the
same WRSR instruction. If the user attempts to set (“1”)
both the IPL and LIP bit in the same time, these bits cannot
be written and therefore they will remain unchanged.
3
BP1
2
BP0
1
WEL
0
RDY
Table 9. BLOCK PROTECTION BITS
Status Register Bits
BP1
0
0
1
1
BP0
0
1
0
1
Array Address Protected
None
6000−7FFF
4000−7FFF
0000−7FFF
Protection
No Protection
Quarter Array Protection
Half Array Protection
Full Array Protection
Table 10. WRITE PROTECT CONDITIONS
WPEN
0
0
1
1
X
X
WP
X
X
Low
Low
High
High
WEL
0
1
0
1
0
1
Protected Blocks
Protected
Protected
Protected
Protected
Protected
Protected
Unprotected Blocks
Protected
Writable
Protected
Writable
Protected
Writable
Status Register
Protected
Writable
Protected
Protected
Protected
Writable
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