AT25PE20
2-Mbit DataFlash-L
Page Erase Serial Flash Memory
PRELIMINARY DATASHEET
Features
Single 1.65V - 3.6V supply
Serial Peripheral Interface (SPI) compatible
Supports SPI modes 0 and 3
Supports RapidS
™
operation
Continuous read capability through entire array
Up to 85MHz
Low-power read option up to 15MHz
Clock-to-output time (t
V
) of 6ns maximum
User configurable page size
256 bytes per page (default)
264 bytes per page (customer selectable option)
One SRAM data buffer (256/264 bytes)
Flexible programming options
Byte/Page Program (1 to 256/264 bytes) directly into main memory
Buffer Write
Buffer to Main Memory Page Program
Single Command Page Read-Modify-Write Option
Flexible erase options
Page Erase (256/264 bytes)
Block Erase (2KB)
Sector Erase (32KB)
Chip Erase (2-Mbits)
128-byte Security Register
128 bytes factory programmed with a unique identifier
Hardware and software controlled reset options
JEDEC Standard Manufacturer and Device ID Read
Low-power dissipation
300nA Ultra-Deep Power-Down current (typical)
5μA Deep Power-Down current (typical)
25μA Standby current (typical)
7mA Active Read current (typical)
Endurance: 100,000 program/erase cycles per page minimum
Data retention: 20 years
Complies with full industrial temperature range
Green (Pb/Halide-free/RoHS compliant) packaging options
8-lead SOIC (0.150ʺ wide and 0.208" wide)
8-pad Ultra-thin DFN (5 x 6 x 0.6mm)
DS-25PE20–139B–3/2018
Description
The Adesto
®
AT25PE20 is a 1.65V minimum, serial-interface sequential access Flash memory is ideally suited for a wide
variety of digital voice, image, program code, and data storage applications. The AT25PE20 also supports the RapidS
serial interface for applications requiring very high speed operation. Its 2,162,688 bits of memory are organized as 1,024
pages of 256 bytes (default) or 264 bytes (customer option) each. In addition to the main memory, AT25PE20 also
contains one SRAM buffer of 256/264 bytes. The Buffer can be used as additional system scratch memory, and E
2
PROM
emulation
(bit or byte alterability) can be easily handled with a self-contained three step read-modify-write operation.
Unlike conventional Flash memories that are accessed randomly with multiple address lines and a parallel interface, the
Adesto DataFlash-L
®
uses a serial interface to sequentially access its data. The simple sequential access dramatically
reduces active pin count, facilitates simplified hardware layout, increases system reliability, minimizes switching noise,
and reduces package size. The device is optimized for use in many commercial and industrial applications where
high-density, low-pin count, low-voltage, and low-power are essential.
To allow for simple in-system re-programmability, AT25PE20 does not require high input voltages for programming. The
device operates from a single 1.65V to 3.6V power supply for the erase and program and read operations. The
AT25PE20 is enabled through the Chip Select pin (CS) and accessed via a 3-wire interface consisting of the Serial Input
(SI), Serial Output (SO), and the Serial Clock (SCK).
All programming and erase cycles are self-timed.
1.
Pin Configurations and Pinouts
Figure 1-1. Pinouts
8-lead SOIC
Top View
CS
SO
WP
GND
1
2
3
4
8
7
6
5
Vcc
RESET
SCK
SI
CS
SO
WP
GND
8-pad UDFN
Top View
(through package)
1
2
3
4
Vcc
RESET
6
SCK
5
SI
8
7
Note:
1.
The metal pad on the bottom of the UDFN package is not internally connected to a voltage potential.
This pad can be a “no connect” or connected to GND.
AT25PE20
DS-25PE20–139B–3/2018
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Table 1-1.
Pin Configurations
Asserted
State
Symbol
Name and Function
Chip Select:
Asserting the CS pin selects the device. When the CS pin is deasserted, the
device will be deselected and normally be placed in the standby mode (not Deep Power-Down
mode) and the output pin (SO) will be in a high-impedance state. When the device is
deselected, data will not be accepted on the input pin (SI).
A high-to-low transition on the CS pin is required to start an operation and a low-to-high
transition is required to end an operation. When ending an internally self-timed operation such
as a program or erase cycle, the device will not enter the standby mode until the completion of
the operation.
Serial Clock:
This pin is used to provide a clock to the device and is used to control the flow of
data to and from the device. Command, address, and input data present on the SI pin is
always latched on the rising edge of SCK, while output data on the SO pin is always clocked
out on the falling edge of SCK.
Serial Input:
The SI pin is used to shift data into the device. The SI pin is used for all data input
including command and address sequences. Data on the SI pin is always latched on the rising
edge of SCK. Data present on the SI pin will be ignored whenever the device is deselected (CS
is deasserted).
Serial Output:
The SO pin is used to shift data out from the device. Data on the SO pin is
always clocked out on the falling edge of SCK. The SO pin will be in a high-impedance state
whenever the device is deselected (CS is deasserted).
Write Protect:
When the WP pin is asserted, all sectors specified for protection by the Sector
Protection Register will be protected against program and erase operations regardless of
whether the Enable Sector Protection command has been issued or not. The WP pin functions
independently of the software controlled protection method. After the WP pin goes low, the
contents of the Sector Protection Register cannot be modified.
Type
CS
Low
Input
SCK
—
Input
SI
—
Input
SO
—
Output
WP
If a program or erase command is issued to the device while the WP pin is asserted, the device
will simply ignore the command and perform no operation. The device will return to the idle
state once the CS pin has been deasserted.
The WP pin is internally pulled-high and may be left floating if hardware controlled protection
will not be used. However, it is recommended that the WP pin also be externally connected to
V
CC
whenever possible.
Reset:
A low state on the reset pin (RESET) will terminate the operation in progress and reset
the internal state machine to an idle state. The device will remain in the reset condition as long
as a low level is present on the RESET pin. Normal operation can resume once the RESET pin
is brought back to a high level.
The device incorporates an internal power-on reset circuit, so there are no restrictions on the
RESET pin during power-on sequences. If this pin and feature is not utilized, then it is
recommended that the RESET pin be driven high externally.
Low
Input
RESET
Low
Input
V
CC
GND
Device Power Supply:
The V
CC
pin is used to supply the source voltage to the device.
Operations at invalid V
CC
voltages may produce spurious results and should not be attempted.
Ground:
The ground reference for the power supply. GND should be connected to the system
ground.
—
—
Power
Ground
AT25PE20
DS-25PE20–139B–3/2018
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2.
Block Diagram
Figure 2-1. Block Diagram
WP
Flash Memory Array
Page (256/264 bytes)
Buffer 1 (256/264 bytes)
SCK
CS
RESET
V
CC
GND
SI
I/O Interface
SO
AT25PE20
DS-25PE20–139B–3/2018
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3.
Memory Array
To provide optimal flexibility, the AT25PE20 memory array is divided into three levels of granularity comprising of sectors,
blocks, and pages.
Figure 3-1, Memory Architecture Diagram
illustrates the breakdown of each level and details the
number of pages per sector and block. Program operations to the DataFlash-L can be done at the full page level or at the
byte level (a variable number of bytes). The erase operations can be performed at the chip, sector, block, or page level.
Figure 3-1. Memory Architecture Diagram
Sector Architecture
Sector 0a = 8 pages
2,048/2,112 bytes
Block Architecture
Sector 0a
Block 0
Block 1
Block 2
Page Architecture
8 Pages
Page 0
Page 1
Sector 0b = 120 pages
30,720/31,680 bytes
Sector 0b
Block 0
Page 6
Block 14
Block 15
Page 7
Page 8
Page 9
Block 17
Sector 1
Block 1
Sector 1 = 128 pages
32,768/33,792 bytes
Block 16
Page 14
Page 15
Block 30
Block 31
Page 16
Page 17
Page 18
Sector 6 = 128 pages
32,768/33,792 bytes
Block 112
Block 113
Sector 7 = 128 pages
32,768/33,792 bytes
Sector 7
Block 126
Block 127
Page 1,022
Page 1,023
Block = 2,048/2,112 bytes
Page = 256/264 bytes
AT25PE20
DS-25PE20–139B–3/2018
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