1
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FM25C640U Rev. B
FM25C640U 64K-Bit SPI Interface Serial CMOS EEPROM
FM25C640U
64K-Bit SPITM Interface
Serial CMOS EEPROM
Block Diagram
February 2002
2002 Fairchild Semiconductor Corporation
Instruction
Decoder
Control Logic
and Clock
Generators
High Voltage
Generator
and
Program
Timer
Instruction
Register
Program
Enable
Data In/Out Register
8 Bits
Data Out
Buffer
Non-Volatile
Status Register
Decoder
Address
Counter/
Register
EEPROM Array
Read/Write Amps
/CS
/HOLD
SCK
V
CC
V
SS
V
PP
/WP
SI
SO
General Description
The FM25C640U is a 64K bit serial interface CMOS EEPROM
(Electrically Erasable Programmable Read-Only Memory). This
device fully conforms to the SPI 4-wire protocol which uses Chip
Select (/CS), Clock (SCK), Data-in (SI) and Data-out (SO) pins to
synchronously control data transfer between the SPI microcontroller
and the EEPROM. In addition, the serial interface allows a minimal
pin count, packaging designed to simplify PC board layout re-
quirements and offers the designer a variety of low voltage and low
power options.
This SPI EEPROM family is designed to work with the 68HC11 or
any other SPI-compatible, high-speed microcontroller and offers
both hardware (/WP pin) and software ("block write") data protec-
tion. For example, entering a 2-bit code into the STATUS REGIS-
TER prevents programming in a selected block of memory and all
programming can be inhibited by connecting the /WP pin to V
SS
;
allowing the user to protect the entire array or a selected section.
In addition, SPI devices feature a /HOLD pin, which allows a
temporary interruption of the datastream into the EEPROM.
Fairchild EEPROMs are designed and tested for applications
requiring high endurance, high reliability, and low power con-
sumption for a continuously reliable non-volatile solution for all
markets.
Functions
I SPI MODE 0 interface
I 64K bits organized as 8K x 8
I Extended 2.7V to 5.5V operating voltage
I 2.1 MHz operation @ 4.5V - 5.5V
I Self-timed programming cycle
I "Programming complete" indicated by STATUS REGISTER
polling
I /WP pin and BLOCK WRITE protection
Features
I Sequential read of entire array
I 32 byte "Page write" mode to minimize total write time per
byte
I /WP pin and BLOCK WRITE protection to prevent inadvert-
ent programming as well as programming ENABLE and
DISABLE opcodes.
I /HOLD pin to suspend data transfer
I Typical 1A standby current (I
SB
) for "L" devices and 0.1
A
standby current for "LZ" devices.
I Endurance: Up to 1,000,000 data changes
I Data retention greater than 40 years
SPITM is a trademark of Motorola Corporation
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FM25C640U Rev. B
FM25C640U 64K-Bit SPI Interface Serial CMOS EEPROM
Connection Diagram
Dual-In-Line Package (N) and SO Package (M8)
Top View
See Package Number N08E (N) and M08A (M8)
Pin Names
/CS
Chip Select Input
SO
Serial Data Output
/WP
Write Protect
V
SS
Ground
SI
Serial Data Input
SCK
Serial Clock Input
/HOLD
Suspends Serial Data
V
CC
Power Supply
Ordering Information
FM
25
C
XX
U
LZ
E
XX
Letter Description
Package
N
8-pin DIP
M8
8-pin SO
Temp. Range
None
0 to 70
C
V
-40 to +125
C
E
-40 to +85
C
Voltage Operating Range
Blank
4.5V to 5.5V
L
2.7V to 5.5V
LZ
2.7V to 5.5V and
<1
A Standby Current
Ultralite
CS100UL Process
Density/Mode
640
64K, mode 0
C
CMOS technology
Interface
25
SPI
FM
Fairchild Nonvolatile
Memory Prefix
/CS
SO
/WP
V
SS
V
CC
/HOLD
SCK
SI
8
7
6
5
1
2
3
4
FM25C640U
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FM25C640U Rev. B
FM25C640U 64K-Bit SPI Interface Serial CMOS EEPROM
Standard Voltage 4.5
V
CC
5.5V Specifications
Absolute Maximum Ratings
(Note 1)
Ambient Storage Temperature
-65
C to +150C
All Input or Output Voltage with
Respect to Ground
+6.5V to -0.3V
Lead Temp. (Soldering, 10 sec.)
+300
C
ESD Rating
2000V
Operating Conditions
Ambient Operating Temperature
FM25C640U
0
C to +70C
FM25C640UE
-40
C to +85C
FM25C640UV
-40
C to +125C
Power Supply (V
CC
)
4.5V to 5.5V
DC and AC Electrical Characteristics
4.5V
V
CC
5.5V (unless otherwise specified)
Symbol
Parameter
Conditions
Min
Max
Units
I
CC
Operating Current
/CS = V
IL
3
mA
I
CCSB
Standby Current
/CS = V
CC
50
A
I
IL
Input Leakage
V
IN
= 0 to V
CC
-1
+1
A
I
OL
Output Leakage
V
OUT
= GND to V
CC
-1
+1
A
V
IL
CMOS Input Low Voltage
-0.3
V
CC
* 0.3
V
V
IH
CMOS Input High Voltage
0.7 * V
CC
V
CC
+ 0.3
V
V
OL
Output Low Voltage
I
OL
= 1.6 mA
0.4
V
V
OH
Output High Voltage
I
OH
= -0.8 mA
V
CC
- 0.8
V
f
OP
SCK Frequency
2.1
MHz
t
RI
Input Rise Time
2.0
s
t
FI
Input Fall Time
2.0
s
t
CLH
Clock High Time
(Note 2)
190
ns
t
CLL
Clock Low Time
(Note 2)
190
ns
t
CSH
Min /CS High Time
(Note 3)
240
ns
t
CSS
/CS Setup Time
240
ns
t
DIS
Data Setup Time
100
ns
t
HDS
/HOLD Setup Time
90
ns
t
CSN
/CS Hold Time
240
ns
t
DIN
Data Hold Time
100
ns
t
HDN
/HOLD Hold Time
90
ns
t
PD
Output Delay
C
L
= 200 pF
240
ns
t
DH
Output Hold Time
0
ns
t
LZ
/HOLD to Output Low Z
100
ns
t
DF
Output Disable Time
C
L
= 200 pF
240
ns
t
HZ
/HOLD to Output High Z
100
ns
t
WP
Write Cycle Time
116 Bytes
10
ms
Capacitance
T
A
= 25
C, f = 2.1/1 MHz (Note 4)
Symbol
Test
Typ Max Units
C
OUT
Output Capacitance
3
8
pF
C
IN
Input Capacitance
2
6
pF
AC Test Conditions
Output Load
C
L
= 200 pF
Input Pulse Levels
0.1 * V
CC
0.9 * V
CC
Timing Measurement Reference Level
0.3 * V
CC
- 0.7 * V
CC
Note 1: Stress above 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 these or any other conditions above those indicated in the operational sections of the specification is not implied. Exposure to absolute maximum rating conditions for
extended periods may affect device reliability.
Note 2: The f
OP
frequency specification specifies a minimum clock period of 1/f
OP
. Therefore, for every f
OP
clock cycle, t
CLH
+ t
CLL
must be equal to or greater than 1/f
OP
. For
example, for a f
OP
of 2.1MHz, the period equals 476ns. In this case if t C
LH
= is set to 190ns, then t
CLL
must be set to a minimum of 286ns.
Note 3: /CS must be brought high for a minimum of t
CSH
between consecutive instruction cycles.
Note 4: This parameter is periodically sampled and not 100% tested.
4
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FM25C640U Rev. B
FM25C640U 64K-Bit SPI Interface Serial CMOS EEPROM
Low Voltage 2.7V
V
CC
4.5V Specifications
Absolute Maximum Ratings
(Note 5)
Ambient Storage Temperature
-65
C to +150C
All Input or Output Voltage with
Respect to Ground
+6.5V to -0.3V
Lead Temp. (Soldering, 10 sec.)
+300
C
ESD Rating
2000V
Operating Conditions
Ambient Operating Temperature
FM25C640UL/LZ
0
C to +70C
FM25C640ULE/LZE
-40
C to +85C
FM25C640ULV
-40
C to +125C
Power Supply (V
CC
)
2.7V4.5V
DC and AC Electrical Characteristics
2.7V
V
CC
4.5V (unless otherwise specified)
25C640UL/LE
25C640ULV
25C640ULZ/ZE
Symbol
Parameter
Part
Conditions
Min.
Max.
Min
Max
Units
I
CC
Operating Current
/CS = V
IL
3
3
mA
I
CCSB
Standby Current
L
/CS = V
CC
10
10
A
LZ
1
N/A
A
I
IL
Input Leakage
V
IN
= 0 to V
CC
-1
1
-1
1
A
I
OL
Output Leakage
V
OUT
= GND to V
CC
-1
1
-1
1
A
V
IL
Input Low Voltage
-0.3
V
CC
* 0.3
-0.3
V
CC
* 0.3
V
V
IH
Input High Voltage
V
CC
* 0.7
V
CC
+ 0.3
V
CC
* 0.7
V
CC
+ 0.3
V
V
OL
Output Low Voltage
I
OL
= 0.8 mA
0.4
0.4
V
V
OH
Output High Voltage
I
OH
= 0.8 mA
V
CC
- 0.8
V
CC
- 0.8
V
f
OP
SCK Frequency
1.0
1.0
MHz
t
RI
Input Rise Time
2.0
2.0
s
t
FI
Input Fall Time
2.0
2.0
s
t
CLH
Clock High Time
(Note 6)
410
410
ns
t
CLL
Clock Low Time
(Note 6)
410
410
ns
t
CSH
Min. /CS High Time
(Note 7)
500
500
ns
t
CSS
/CS Setup Time
500
500
ns
t
DIS
Data Setup Time
100
100
ns
t
HDS
/HOLD Setup Time
240
240
ns
t
CSN
/CS Hold Time
500
500
ns
t
DIN
Data Hold Time
100
100
ns
t
HDN
/HOLD Hold Time
240
240
ns
t
PD
Output Delay
C
L
= 200 pF
500
500
ns
t
DH
Output Hold Time
0
0
ns
t
LZ
/HOLD Output Low Z
240
240
ns
t
DF
Output Disable Time
C
L
= 200 pF
500
500
ns
t
HZ
/HOLD to Output Hi Z
240
240
ns
t
WP
Write Cycle Time
1-16 Bytes
15
15
ms
Capacitance
T
A
= 25
C, f = 2.1/1 MHz (Note 8)
Symbol
Test
Typ Max Units
C
OUT
Output Capacitance
3
8
pF
C
IN
Input Capacitance
2
6
pF
AC Test Conditions
Output Load
C
L
= 200pF
Input Pulse Levels
0.1 * V
CC
- 0.9 * V
CC
Timing Measurement Reference Level
0.3 * V
CC
- 0.7 * V
CC
Note 5: Stress above 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 these or any other conditions above those indicated in the operational sections of the specification is not implied. Exposure to absolute maximum rating conditions for extended
periods may affect device reliability.
Note 6: The f
OP
frequency specification specifies a minimum clock period of 1/f
OP
. Therefore, for every f
OP
clock cycle, t
CLH
+ t
CLL
must be equal to or greater than 1/f
OP
. For
example, for a f
OP
of 1MHz, the period equals 1000ns. In this case if t
CLH
= is set to 410ns, then t
CLL
must be set to a minimum of 590ns.
Note 7: /CS must be brought high for a minimum of t
CSH
between consecutive instruction cycles.
Note 8: This parameter is periodically sampled and not 100% tested.
5
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FM25C640U Rev. B
FM25C640U 64K-Bit SPI Interface Serial CMOS EEPROM
FIGURE 1. Synchronous Data Timing Diagram
tCSS
tCLH
tCLL
tCSH
tDF
tPD
tDIS
tDIH
tDH
tCSI
SCK
SI
SO
/CS
Valid Input
Valid Output
High Z
Mode 3
Mode 3
Mode 0
Mode 0
SCK
CS
SO
/HOLD
Output (n+1)
Output (n)
Output (n)
Output (n+2)
tHDS
tHZ
tLZ
tHDH
tHDS tHDH
tDIS
High Z
SI
Input (n+1)
Input (n)
Input (n)
Input (n+2)
Don't Care
Low state ( /CS = 0)
Don't Care
FIGURE 3. HOLD Timing
FIGURE 2. SPI Protocol
SCK
SI
SO
/CS
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Don't Care
High Z
Mode 3
Mode 3
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