Features
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Serial Peripheral Interface (SPI) Compatible
Supports SPI Modes 0 (0,0) and 3 (1,1)
33 MHz Clock Rate
Byte Mode and 256-byte Page Mode for Program Operations
Sector Architecture:
– Four Sectors with 64K Bytes Each
– 256 Pages per Sector
Product Identification Mode
Low-voltage Operation
– 2.7 (V
CC
= 2.7V to 3.6V)
Sector Write Protection
– Protect 1/4, 1/2 or Entire Array
Write Protect (WP) Pin and Write Disable Instructions for
both Hardware and Software Data Protection
Self-timed Program Cycle (30
µs/Byte
Typical)
Self-timed Sector Erase Cycle (1 second/Sector Typical)
Single Cycle Reprogramming (Erase and Program) for Status Register
High Reliability
– Endurance: 10,000 Write Cycles Typical
– Data Retention: 20 Years
8-lead JEDEC SOIC and 8-lead Ultra Thin Small Array (SAP) Packages
Die Sales: Wafer Form, Tape and Reel and Bumped Wafers
2Mbit High
Speed SPI
Serial Flash
Memory
2M (262,144 x 8)
AT25F2048
Description
The AT25F2048 provides 2,097,152 bits of serial reprogrammable Flash memory
organized as 262,144 words of 8 bits each. The device is optimized for use in many
industrial and commercial applications where low-power and low-voltage operation
are essential. The AT25F2048 is available in a space-saving 8-lead JEDEC SOIC and
Ultra Thin SAP package.
Pin Configurations
Pin Name
CS
SCK
SI
SO
GND
VCC
WP
HOLD
Function
Chip Select
Serial Data Clock
Serial Data Input
Serial Data Output
Ground
Power Supply
Write Protect
Suspends Serial Input
VCC
HOLD
SCK
SI
1
2
3
4
8
7
6
5
CS
SO
WP
GND
8-lead Ultra Thin SAP
CS
SO
WP
GND
8-lead SOIC
1
2
3
4
8
7
6
5
VCC
HOLD
SCK
SI
Bottom View
Rev. 2455I–SFLSH–5/07
1
The AT25F2048 is enabled through the Chip Select pin (CS) and accessed via a 3-wire
interface consisting of Serial Data Input (SI), Serial Data Output (SO), and Serial Clock
(SCK). All write cycles are completely self-timed.
Block Write protection for top 1/4, top 1/2 or the entire memory array is enabled by pro-
gramming the status register. Separate write enable and write disable instructions are
provided for additional data protection. Hardware data protection is provided via the WP
pin to protect against inadvertent write attempts to the status register. The HOLD pin
may be used to suspend any serial communication without resetting the serial
sequence.
Absolute Maximum Ratings*
Operating Temperature.................................... -40°C to +85°C
Storage Temperature ..................................... -65°C to +150°C
Voltage on Any Pin
with Respect to Ground .....................................-1.0V to +3.6V
Maximum Operating Voltage ............................................ 4.2V
DC Output Current........................................................ 5.0 mA
*NOTICE:
Stresses beyond those listed under “Absolute
Maximum Ratings” may cause permanent dam-
age to the device. This is a stress rating only and
functional operation of the device at these or any
other conditions beyond those indicated in the
operational sections of this specification is not
implied. Exposure to absolute maximum rating
conditions for extended periods may affect
device reliability.
Figure 1.
Block Diagram
262,144 x 8
2
AT25F2048
2455I–SFLSH–5/07
AT25F2048
Table 1.
Pin Capacitance
(1)
Applicable over recommended operating range from T
A
= 25°C, f = 1.0 MHz, V
CC
= +3.6V (unless otherwise noted)
Symbol
C
OUT
C
IN
Note:
Test Conditions
Output Capacitance (SO)
Input Capacitance (CS, SCK, SI, WP, HOLD)
1. This parameter is characterized and is not 100% tested.
Max
8
6
Units
pF
pF
Conditions
V
OUT
= 0V
V
IN
= 0V
Table 2.
DC Characteristics (Preliminary – Subject to Change)
Applicable over recommended operating range from: T
AI
= -40°C to +85°C, V
CC
= +2.7V to +3.6V,
T
AC
= 0°C to +70°C, V
CC
= +2.7V to +3.6V (unless otherwise noted)
Symbol
V
CC
I
CC1
I
CC2
I
SB
I
IL
I
OL
V
IL(1)
V
IH(1)
V
OL
V
OH
Note:
Parameter
Supply Voltage
Supply Current
Supply Current
Standby Current
Input Leakage
Output Leakage
Input Low Voltage
Input High Voltage
Output Low Voltage
Output High Voltage
2.7V
≤
V
CC
≤
3.6V
I
OL
= 0.15 mA
I
OH
= -100
µA
V
CC
- 0.2
V
CC
= 3.6V at 33 MHz, SO = Open Read
V
CC
= 3.6V at 33 MHz, SO = Open Write
V
CC
= 2.7V, CS = V
CC
V
IN
= 0V to V
CC
V
IN
= 0V to V
CC
, T
AC
= 0°C to 70°C
-3.0
-3.0
-0.6
V
CC
x 0.7
Test Condition
Min
2.7
10.0
25.0
2.0
Typ
Max
3.6
17.0
45.0
10.0
3.0
3.0
V
CC
x 0.3
V
CC
+ 0.5
0.2
Units
V
mA
mA
µA
µA
µA
V
V
V
V
1. V
IL
and V
IH
max are reference only and are not tested.
3
2455I–SFLSH–5/07
Table 3.
AC Characteristics (Preliminary – Subject to Change)
Applicable over recommended operating range from T
A
= -40°C to +85°C, V
CC
= +2.7V to +3.6V
C
L
= 1 TTL Gate and 30 pF (unless otherwise noted)
Symbol
f
SCK
t
RI
t
FI
t
WH
t
WL
t
CS
t
CSS
t
CSH
t
SU
t
H
t
HD
t
CD
t
V
t
HO
t
LZ
t
HZ
t
DIS
t
EC
t
SR
t
BPC
Endurance
(2)
Notes:
Parameter
SCK Clock Frequency
Input Rise Time
Input Fall Time
SCK High Time
SCK Low Time
CS High Time
CS Setup Time
CS Hold Time
Data In Setup Time
Data In Hold Time
Hold Setup Time
Hold Hold Time
Output Valid
Output Hold Time
Hold to Output Low Z
Hold to Output High Z
Output Disable Time
Erase Cycle Time per Sector
Status Register Write Cycle Time
Byte Program Cycle Time
(1)
30
10K
0
200
200
100
1.0
60
50
9
9
25
25
10
5
5
15
15
9
Min
0
Typ
Max
33
20
20
Units
MHz
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
s
ms
µs
Write Cycles
(3)
1. The programming time for n bytes will be equal to n x t
BPC
.
2. This parameter is ensured by characterization at 3.0V, 25°C only.
3. One write cycle consists of erasing a sector, followed by programming the same sector.
4
AT25F2048
2455I–SFLSH–5/07
AT25F2048
Serial Interface
Description
MASTER:
The device that generates the serial clock.
SLAVE:
Because the serial clock pin (SCK) is always an input, the AT25F2048 always
operates as a slave.
TRANSMITTER/RECEIVER:
The AT25F2048 has separate pins designated for data
transmission (SO) and reception (SI).
MSB:
The Most Significant Bit (MSB) is the first bit transmitted and received.
SERIAL OP-CODE:
After the device is selected with CS going low, the first byte will be
received. This byte contains the op-code that defines the operations to be performed.
INVALID OP-CODE:
If an invalid op-code is received, no data will be shifted into the
AT25F2048, and the serial output pin (SO) will remain in a high impedance state until
the falling edge of CS is detected again. This will reinitialize the serial communication.
CHIP SELECT:
The AT25F2048 is selected when the CS pin is low. When the device is
not selected, data will not be accepted via the SI pin, and the serial output pin (SO) will
remain in a high impedance state.
HOLD:
The HOLD pin is used in conjunction with the CS pin to select the AT25F2048.
When the device is selected and a serial sequence is underway, HOLD can be used to
pause the serial communication with the master device without resetting the serial
sequence. To pause, the HOLD pin must be brought low while the SCK pin is low. To
resume serial communication, the HOLD pin is brought high while the SCK pin is low
(SCK may still toggle during HOLD). Inputs to the SI pin will be ignored while the SO pin
is in the high impedance state.
WRITE PROTECT:
The 25F2048 has a write lockout feature that can be activated by
asserting the write protect pin (WP). When the lockout feature is activated, locked-out
sectors will be read only. The write protect pin will allow normal read/write operations
when held high. When the WP is brought low and WPEN bit is “1”, all write operations to
the status register are inhibited. WP going low while CS is still low will interrupt a write to
the status register. If the internal status register write cycle has already been initiated,
WP going low will have no effect on any write operation to the status register. The WP
pin function is blocked when the WPEN bit in the status register is “0”. This will allow the
user to install the AT25F2048 in a system with the WP pin tied to ground and still be
able to write to the status register. All WP pin functions are enabled when the WPEN bit
is set to “1”.
5
2455I–SFLSH–5/07
Embedded System
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