• Individual Sector Protection with Global Protect/Unprotect Feature
– One 16-Kbyte Top Sector
– Two 8-Kbyte Sectors
– One 32-Kbyte Sector
– Seven 64-Kbyte Sectors
• Hardware Controlled Locking of Protected Sectors via WP pin
• Flexible Programming Options
– Byte/Page Program (1 to 256 Bytes)
– Sequential Program Mode Capability
• Fast Program and Erase Times
– 1.2 ms Typical Page Program (256 Bytes) Time
– 50 ms Typical 4-Kbyte Block Erase Time
– 250 ms Typical 32-Kbyte Block Erase Time
– 400 ms Typical 64-Kbyte Block Erase Time
• Automatic Checking and Reporting of Erase/Program Failures
• JEDEC Standard Manufacturer and Device ID Read Methodology
• Low Power Dissipation
– 5 mA Active Read Current (Typical)
– 15 µA Deep Power-down Current (Typical)
• Endurance: 100,000 Program/Erase Cycles
• Data Retention: 20 Years
• Complies with Full Industrial Temperature Range
• Industry Standard Green (Pb/Halide-free/RoHS Compliant) Package Options
The AT25DF041A is a serial interface Flash memory device designed for use in a
wide variety of high-volume consumer-based applications in which program code is
shadowed from Flash memory into embedded or external RAM for execution. The
flexible erase architecture of the AT25DF041A, with its erase granularity as small as
4 Kbytes, makes it ideal for data storage as well, eliminating the need for additional
data storage EEPROM devices.
3668E–DFLASH–11/2012
The physical sectoring and the erase block sizes of the AT25DF041A have been optimized to
meet the needs of today’s code and data storage applications. By optimizing the size of the
physical sectors and erase blocks, the memory space can be used much more efficiently.
Because certain code modules and data storage segments must reside by themselves in their
own protected sectors, the wasted and unused memory space that occurs with large sectored
and large block erase Flash memory devices can be greatly reduced. This increased memory
space efficiency allows additional code routines and data storage segments to be added while
still maintaining the same overall device density.
The AT25DF041A also offers a sophisticated method for protecting individual sectors against
erroneous or malicious program and erase operations. By providing the ability to individually protect and unprotect sectors, a system can unprotect a specific sector to modify its contents while
keeping the remaining sectors of the memory array securely protected. This is useful in applications where program code is patched or updated on a subroutine or module basis, or in
applications where data storage segments need to be modified without running the risk of errant
modifications to the program code segments. In addition to individual sector protection capabilities, the AT25DF041A incorporates Global Protect and Global Unprotect features that allow the
entire memory array to be either protected or unprotected all at once. This reduces overhead
during the manufacturing process since sectors do not have to be unprotected one-by-one prior
to initial programming.
Specifically designed for use in 2.5-volt or 3-volt systems, the AT25DF041A supports read, program, and erase operations with a supply voltage range of 2.3V to 3.6V or 2.7V to 3.6V. No
separate voltage is required for programming and erasing.
2
AT25DF041A
3668E–DFLASH–11/2012
2.Pin Descriptions and Pinouts
Table 2-1.Pin Descriptions
SymbolName and Function
CS
SCK
SI
SO
WP
HOLD
V
CC
GND
CHIP SELECT: Asserting the
device will be deselected and normally be placed in standby mode (not Deep Power-down mode),
and the SO pin will be in a high-impedance state. When the device is deselected, data will not be
accepted on the SI pin.
A high-to-low transition on the
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.
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.
WRITE PROTECT: The
section “Protection Commands and Features” on page 15 for more details on protection features
and the
The
WP pin.
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
whenever possible.
HOLD: The
HOLD pin is used to temporarily pause serial communication without deselecting or
resetting the device. While the
SI pin will be ignored, and the SO pin will be in a high-impedance state.
The
CS pin must be asserted, and the SCK pin must be in the low state in order for a Hold
condition to start. A Hold condition pauses serial communication only and does not have an effect
on internally self-timed operations such as a program or erase cycle. Please refer to section “Hold”
on page 30 for additional details on the Hold operation.
The
HOLD pin is internally pulled-high and may be left floating if the Hold function will not be used.
However, it is recommended that the
possible.
DEVICE POWER SUPPLY: The VCCpin is used to supply the source voltage to the device.
Operations at invalid V
GROUND: The ground reference for the power supply. GND should be connected to the
system ground.
CS pin selects the device. When the CS pin is deasserted, the
CS pin is required to start an operation, and a low-to-high transition
WP pin controls the hardware locking feature of the device. Please refer to
HOLD pin is asserted, transitions on the SCK pin and data on the
HOLD pin also be externally connected to VCCwhenever
voltages may produce spurious results and should not be attempted.
CC
WP pin also be externally connected to V
AT25DF041A
Asserted
StateType
LowInput
Input
Input
Output
LowInput
CC
LowInput
Power
Power
3668E–DFLASH–11/2012
Figure 2-1.8-SOIC Top ViewFigure 2-2.8-UDFN Top View
CS
SO
WP
GND
1
1
2
3
4
VCC
8
HOLD
7
SCK
6
SI
5
CS
SO
WP
GND
2
3
4
8
7
6
5
VCC
HOLD
SCK
SI
3
3.Block Diagram
CS
SCK
SI
SO
WP
INTERFACE
CONTROL
4.Memory Array
CONTROL AND
PROTECTION LOGIC
AND
LOGIC
ADDRESS LATCH
To provide the greatest flexibility, the memory array of the AT25DF041A can be erased in four
levels of granularity including a full chip erase. In addition, the array has been divided into physical sectors of various sizes, of which each sector can be individually protected from program
and erase operations. The sizes of the physical sectors are optimized for both code and data
storage applications, allowing both code and data segments to reside in their own isolated
regions. Figure 4-1 on page 5 illustrates the breakdown of each erase level as well as the breakdown of each physical sector.
Y-DECODER
X-DECODER
I/O BUFFERS
AND LATCHES
SRAM
DATA BUFFER
Y-GATING
FLASH
MEMORY
ARRAY
4
AT25DF041A
3668E–DFLASH–11/2012
Figure 4-1.Memory Architecture Diagram
64KB
(Sector 0)
32KB
32KB
• • •
64KB
32KB
32KB
• • •
• • •
• • •
64KB
32KB
32KB
• • •
64KB
(Sector 6)
64KB
16KB
(Sector 10)
8KB
(Sector 9)
8KB
(Sector 8)
32KB
(Sector 7)
r
Block Erase DetailPage Program Detail
AT25DF041A
Internal Sectoring fo
Sector ProtectionBlock EraseBlock EraseBlock ErasePage Program
The AT25DF041A is controlled by a set of instructions that are sent from a host controller, commonly referred to as the SPI Master. The SPI Master communicates with the AT25DF041A via
the SPI bus which is comprised of four signal lines: Chip Select (
Input (SI), and Serial Output (SO).
The SPI protocol defines a total of four modes of operation (mode 0, 1, 2, or 3) with each mode
differing in respect to the SCK polarity and phase and how the polarity and phase control the
flow of data on the SPI bus. The AT25DF041A supports the two most common modes, SPI
modes 0 and 3. The only difference between SPI modes 0 and 3 is the polarity of the SCK signal
when in the inactive state (when the SPI Master is in standby mode and not transferring any
data). With SPI modes 0 and 3, data is always latched in on the rising edge of SCK and always
output on the falling edge of SCK.
Figure 5-1.SPI Mode 0 and 3
CS
SCK
CS), Serial Clock (SCK), Serial
SI
SO
MSBLSB
6.Commands and Addressing
A valid instruction or operation must always be started by first asserting the CS pin. After the CS
pin has been asserted, the SPI Master must then clock out a valid 8-bit opcode on the SPI bus.
Following the opcode, instruction dependent information such as address and data bytes would
then be clocked out by the SPI Master. All opcode, address, and data bytes are transferred with
the most significant bit (MSB) first. An operation is ended by deasserting the CS pin.
Opcodes not supported by the AT25DF041A will be ignored by the device and no operation will
be started. The device will continue to ignore any data presented on the SI pin until the start of
the next operation (CS pin being deasserted and then reasserted). In addition, if the CSpinis
deasserted before complete opcode and address information is sent to the device, then no operation will be performed and the device will simply return to the idle state and wait for the next
operation.
Addressing of the device requires a total of three bytes of information to be sent, representing
address bits A23 - A0. Since the upper address limit of the AT25DF041A memory array is
07FFFFh, address bits A23 - A19 are always ignored by the device.
MSB
LSB
6
AT25DF041A
3668E–DFLASH–11/2012
AT25DF041A
Table 6-1.Command Listing
CommandOpcodeAddress BytesDummy BytesData Bytes
Read Commands
Read Array0Bh0000 1011311+
Read Array (Low Frequency)03h0000 0011301+
Program and Erase Commands
Block Erase (4 Kbytes)20h0010 0000300
Block Erase (32 Kbytes)52h0101 0010300
Block Erase (64 Kbytes)D8h1101 1000300
Chip Erase
Byte/Page Program (1 to 256 Bytes)02h0000 0010301+
Sequential Program Mode
Protection Commands
60h0110 0000000
C7h1100 0111000
ADh1010 11013, 0
AFh1010 11113, 0
(1)
(1)
01
01
Write Enable06h0000 0110000
Write Disable04h0000 0100000
Protect Sector36h0011 0110300
Unprotect Sector39h0011 1001300
Global Protect/UnprotectUse Write Status Register command
Read Sector Protection Registers3Ch0011 1100301+
Status Register Commands
Read Status Register05h0000 0101001+
Write Status Register01h0000 0001001
Miscellaneous Commands
Read Manufacturer and Device ID9Fh1001 1111001 to 4
Deep Power-downB9h1011 1001000
Resume from Deep Power-downABh1010 1011000
Note:1. Three address bytes are only required for the first operation to designate the address to start programming at. Afterwards,
the internal address counter automatically increments, so subsequent Sequential Program Mode operations only require
clocking in of the opcode and the data byte until the Sequential Program Mode has been exited.
3668E–DFLASH–11/2012
7
7.Read Commands
7.1Read Array
The Read Array command can be used to sequentially read a continuous stream of data from
the device by simply providing the SCK signal once the initial starting address has been specified. The device incorporates an internal address counter that automatically increments on every
clock cycle.
Two opcodes, 0Bh and 03h, can be used for the Read Array command. The use of each opcode
depends on the maximum SCK frequency that will be used to read data from the device. The
0Bh opcode can be used at any SCK frequency up to the maximum specified by f
opcode can be used for lower frequency read operations up to the maximum specified by f
To perform the Read Array operation, the CS pin must first be asserted and the appropriate
opcode (0Bh or 03h) must be clocked into the device. After the opcode has been clocked in, the
three address bytes must be clocked in to specify the starting address location of the first byte to
read within the memory array. If the 0Bh opcode is used, then one don't care byte must also be
clocked in after the three address bytes.
After the three address bytes (and the one don't care byte if using opcode 0Bh) have been
clocked in, additional clock cycles will result in serial data being output on the SO pin. The data
is always output with the MSB of a byte first. When the last byte (07FFFFh) of the memory array
has been read, the device will continue reading back at the beginning of the array (000000h).
No delays will be incurred when wrapping around from the end of the array to the beginning
of the array.
.The03h
SCK
RDLF
.
Deasserting the CS pin will terminate the read operation and put the SO pin into a high-impedance state. The CS pin can be deasserted at any time and does not require that a full byte
of data be read.
The Byte/Page Program command allows anywhere from a single byte of data to 256 bytes of
data to be programmed into previously erased memory locations. An erased memory location is
one that has all eight bits set to the logical “1” state (a byte value of FFh). Before a Byte/Page
Program command can be started, the Write Enable command must have been previously
issued to the device (see “Write Enable” on page 15 command description) to set the Write
Enable Latch (WEL) bit of the Status Register to a logical “1” state.
To perform a Byte/Page Program command, an opcode of 02h must be clocked into the device
followed by the three address bytes denoting the first byte location of the memory array to begin
programming at. After the address bytes have been clocked in, data can then be clocked into the
device and will be stored in an internal buffer.
If the starting memory address denoted by A23 - A0 does not fall on an even 256-byte page
boundary (A7 - A0 are not all 0’s), then special circumstances regarding which memory locations
will be programmed will apply. In this situation, any data that is sent to the device that goes
beyond the end of the page will wrap around back to the beginning of the same page. For example, if the starting address denoted by A23 - A0 is 0000FEh, and three bytes of data are sent to
the device, then the first two bytes of data will be programmed at addresses 0000FEh and
0000FFh while the last byte of data will be programmed at address 000000h. The remaining
bytes in the page (addresses 000001h through 0000FDh) will be unaffected and will not change.
In addition, if more than 256 bytes of data are sent to the device, then only the last 256 bytes
sent will be latched into the internal buffer.
AT25DF041A
When the
gram it into the appropriate memory array locations based on the starting address specified by
A23 - A0 and the number of data bytes sent to the device. If less than 256 bytes of data were
sent to the device, then the remaining bytes within the page will not be altered. The programming of the data bytes is internally self-timed and should take place in a time of tPP.
The three address bytes and at least one complete byte of data must be clocked into the device
before the CS pin is deasserted, and the CS pin must be deasserted on even byte boundaries
(multiples of eight bits); otherwise, the device will abort the operation and no data will be programmed into the memory array. In addition, if the address specified by A23 - A0 points to a
memory location within a sector that is in the protected state (see section “Protect Sector” on
page 16), then the Byte/Page Program command will not be executed, and the device will return
to the idle state once the CS pin has been deasserted. The WEL bit in the Status Register will be
reset back to the logical “0” state if the program cycle aborts due to an incomplete address being
sent, an incomplete byte of data being sent, or because the memory location to be programmed
is protected.
While the device is programming, the Status Register can be read and will indicate that the
device is busy. For faster throughput, it is recommended that the Status Register be polled
rather than waiting the tBPor tPPtime to determine if the data bytes have finished programming.
At some point before the program cycle completes, the WEL bit in the Status Register will be
reset back to the logical “0” state.
The device also incorporates an intelligent programming algorithm that can detect when a byte
location fails to program properly. If a programming error arises, it will be indicated by the EPE
bit in the Status Register.
CS pin is deasserted, the device will take the data stored in the internal buffer and pro-
3668E–DFLASH–11/2012
9
The Byte/Page Program mode is the default programming mode after the device powers-up or
resumes from a device reset.
Figure 8-1.Byte Program
CS
SCK
SI
SO
Figure 8-2.Page Program
CS
SCK
SI
SO
00000010
MSBMSB
HIGH-IMPEDANCE
2310
OPCODE
00000010
MSBMSB
HIGH-IMPEDANCE
2310
OPCODE
6754983937 383336353431 3229 30
ADDRESS BITS A23-A0DATA IN BYTE 1
AAAAAA
6754101198123937 383336353431 3229 30
ADDRESS BITS A23-A0DATA IN
AAAAAAAA A
DDDDDDDD
MSB
DDDDDDDD
MSB
DATA IN BYTE n
DDDDDDDD
MSB
8.2Sequential Program Mode
The Sequential Program Mode improves throughput over the Byte/Page Program command
when the Byte/Page Program command is used to program single bytes only into consecutive
address locations. For example, some systems may be designed to program only a single byte
of information at a time and cannot utilize a buffered Page Program operation due to design
restrictions. In such a case, the system would normally have to perform multiple Byte Program
operations in order to program data into sequential memory locations. This approach can add
considerable system overhead and SPI bus traffic.
The Sequential Programming Mode helps reduce system overhead and bus traffic by incorporating an internal address counter that keeps track of the byte location to program, thereby
eliminating the need to supply an address sequence to the device for every byte to program.
When using the Sequential Program mode, all address locations to be programmed must be in
the erased state. Before the Sequential Program mode can first be entered, the Write Enable
command must have been previously issued to the device to set the WEL bit of the Status Register to a logical “1” state.
To start the Sequential Program Mode, the CS pin must first be asserted, and either an opcode
of ADh or AFh must be clocked into the device. For the first program cycle, three address bytes
must be clocked in after the opcode to designate the first byte location to program. After the
address bytes have been clocked in, the byte of data to be programmed can be sent to the
10
AT25DF041A
3668E–DFLASH–11/2012
AT25DF041A
device. Deasserting the CS pin will start the internally self-timed program operation, and the byte
of data will be programmed into the memory location specified by A23 - A0.
After the first byte has been successfully programmed, a second byte can be programmed by
simply reasserting the CS pin, clocking in the ADh or AFh opcode, and then clocking in the next
byte of data. When the
the next sequential memory location. The process would be repeated for any additional bytes.
There is no need to reissue the Write Enable command once the Sequential Program Mode has
been entered.
When the last desired byte has been programmed into the memory array, the Sequential
Program Mode operation can be terminated by reasserting the
Write Disable command to the device to reset the WEL bit in the Status Register back to the
logical “0” state.
If more than one byte of data is ever clocked in during each program cycle, then only the last
byte of data sent on the SI pin will be stored in the internal latches. The programming of each
byte is internally self-timed and should take place in a time of tBP. For each program cycle, a
complete byte of data must be clocked into the device before the CS pin is deasserted, and the
CS pin must be deasserted on even byte boundaries (multiples of eight bits); otherwise, the
device will abort the operation, the byte of data will not be programmed into the memory array,
and the WEL bit in the Status Register will be reset back to the logical “0” state.
CS pin is deasserted, the second byte of data will be programmed into
CS pin and sending the
If the address initially specified by A23 - A0 points to a memory location within a sector that is in
the protected state, then the Sequential Program Mode command will not be executed, and the
device will return to the idle state once the CS pin has been deasserted. The WEL bit in the Status Register will also be reset back to the logical “0” state.
There is no address wrapping when using the Sequential Program Mode. Therefore, when the
last byte (07FFFFh) of the memory array has been programmed, the device will automatically
exit the Sequential Program mode and reset the WEL bit in the Status Register back to the logical “0” state. In addition, the Sequential Program mode will not automatically skip over protected
sectors; therefore, once the highest unprotected memory location in a programming sequence
has been programmed, the device will automatically exit the Sequential Program mode and
reset the WEL bit in the Status Register. For example, if Sector 1 was protected and Sector 0
was currently being programmed, once the last byte of Sector 0 was programmed, the Sequential Program mode would automatically end. To continue programming with Sector 2, the
Sequential Program mode would have to be restarted by supplying the ADh or AFh opcode, the
three address bytes, and the first byte of Sector 2 to program.
While the device is programming a byte, the Status Register can be read and will indicate that
the device is busy. For faster throughput, it is recommended that the Status Register be polled at
the end of each program cycle rather than waiting the tBPtime to determine if the byte has finished programming before starting the next Sequential Program mode cycle.
The device also incorporates an intelligent programming algorithm that can detect when a byte
location fails to program properly. If a programming error arises, it will be indicated by the EPE
bit in the Status Register.
3668E–DFLASH–11/2012
11
Figure 8-3.Sequential Program Mode – Status Register Polling
CS
Seqeuntial Program Mode
Command
Opcode
SI
SO
Note: Each transitionshown for SI represents one byte (8 bits)
A23-16 A15-8A7-005hData
First Address to Program
HIGH-IMPEDANCE
Status Register Read
Command
STATUS REGISTER
Seqeuntial Program Mode
Command
Opcode
DATA
Seqeuntial Program Mode
Data05h04h
STATUS REGISTER
DATA
Figure 8-4.Sequential Program Mode – Waiting Maximum Byte Program Time
CS
t
BP
Seqeuntial Program Mode
Command
Opcode
SI
SO
Note: Each transitionshown for SI represents one byte (8 bits)
A23-16 A15-8A7-0Data
First Address to Program
HIGH-IMPEDANCE
Seqeuntial Program Mode
Command
Opcode
Data04h
t
BP
Seqeuntial Program Mode
Command
Command
Opcode
Opcode
Data05h
Data
Write Disable
Command
t
BP
STATUS REGISTER
Write Disable
Command
DATA
8.3Block Erase
A block of 4, 32, or 64 Kbytes can be erased (all bits set to the logical “1” state) in a single operation by using one of three different opcodes for the Block Erase command. An opcode of 20h is
used for a 4-Kbyte erase, an opcode of 52h is used for a 32-Kbyte erase, and an opcode of D8h
is used for a 64-Kbyte erase. Before a Block Erase command can be started, the Write Enable
command must have been previously issued to the device to set the WEL bit of the Status Register to a logical “1” state.
To perform a Block Erase, the CS pin must first be asserted and the appropriate opcode (20h,
52h or D8h) must be clocked into the device. After the opcode has been clocked in, the three
address bytes specifying an address within the 4-, 32-, or 64-Kbyte block to be erased must be
clocked in. Any additional data clocked into the device will be ignored. When the CS pin is deasserted, the device will erase the appropriate block. The erasing of the block is internally selftimed and should take place in a time of t
BLKE
.
Since the Block Erase command erases a region of bytes, the lower order address bits do not
need to be decoded by the device. Therefore, for a 4-Kbyte erase, address bits A11 - A0 will be
ignored by the device and their values can be either a logical “1” or “0”. For a 32-Kbyte erase,
address bits A14 - A0 will be ignored, and for a 64-Kbyte erase, address bits A15 - A0 will be
ignored by the device. Despite the lower order address bits not being decoded by the device, the
complete three address bytes must still be clocked into the device before the CS pin is deasserted, and the CS pin must be deasserted on an even byte boundary (multiples of eight bits);
otherwise, the device will abort the operation and no erase operation will be performed.
12
AT25DF041A
3668E–DFLASH–11/2012
AT25DF041A
If the address specified by A23 - A0 points to a memory location within a sector that is in the protected state, then the Block Erase command will not be executed, and the device will return to
the idle state once the
sizes of 32K and 64 Kbytes, more than one physical sector may be erased (e.g. sectors 18
through 15) at one time. Therefore, in order to erase a larger block that may span more than one
sector, all of the sectors in the span must be in the unprotected state. If one of the physical sectors within the span is in the protected state, then the device will ignore the Block Erase
command and will return to the idle state once the CS pin is deasserted.
The WEL bit in the Status Register will be reset back to the logical “0” state if the erase cycle
aborts due to an incomplete address being sent or because a memory location within the region
to be erased is protected.
While the device is executing a successful erase cycle, the Status Register can be read and will
indicate that the device is busy. For faster throughput, it is recommended that the Status Register be polled rather than waiting the t
some point before the erase cycle completes, the WEL bit in the Status Register will be reset
back to the logical “0” state.
The device also incorporates an intelligent erase algorithm that can detect when a byte location
fails to erase properly. If an erase error occurs, it will be indicated by the EPE bit in the Status
Register.
CS pin has been deasserted. In addition, with the larger Block Erase
time to determine if the device has finished erasing. At
BLKE
Figure 8-5.Block Erase
CS
SCK
SI
SO
CCCCCCCC
MSBMSB
HIGH-IMPEDANCE
2310
OPCODE
6754101198123129 3027 2826
ADDRESS BITS A23-A0
AAAAAAAA AA A A
3668E–DFLASH–11/2012
13
8.4Chip Erase
The entire memory array can be erased in a single operation by using the Chip Erase command.
Before a Chip Erase command can be started, the Write Enable command must have been previously issued to the device to set the WEL bit of the Status Register to a logical “1” state.
Two opcodes, 60h and C7h, can be used for the Chip Erase command. There is no difference in
device functionality when utilizing the two opcodes, so they can be used interchangeably. To
perform a Chip Erase, one of the two opcodes (60h or C7h) must be clocked into the device.
Since the entire memory array is to be erased, no address bytes need to be clocked into the
device, and any data clocked in after the opcode will be ignored. When the
CS pin is deasserted,
the device will erase the entire memory array. The erasing of the device is internally self-timed
and should take place in a time of t
The complete opcode must be clocked into the device before the
CHPE
.
CS pin is deasserted, and the
CS pin must be deasserted on an even byte boundary (multiples of eight bits); otherwise, no
erase will be performed. In addition, if any sector of the memory array is in the protected state,
then the Chip Erase command will not be executed, and the device will return to the idle state
once the CS pin has been deasserted. The WEL bit in the Status Register will be reset back to
the logical “0” state if a sector is in the protected state.
While the device is executing a successful erase cycle, the Status Register can be read and will
indicate that the device is busy. For faster throughput, it is recommended that the Status Register be polled rather than waiting the t
time to determine if the device has finished erasing. At
CHPE
some point before the erase cycle completes, the WEL bit in the Status Register will be reset
back to the logical “0” state.
The device also incorporates an intelligent erase algorithm that can detect when a byte location
fails to erase properly. If an erase error occurs, it will be indicated by the EPE bit in the Status
Register.
Figure 8-6.Chip Erase
CS
2310
6754
SCK
OPCODE
SI
SO
CCCCCCCC
MSB
HIGH-IMPEDANCE
14
AT25DF041A
3668E–DFLASH–11/2012
9.Protection Commands and Features
9.1Write Enable
The Write Enable command is used to set the Write Enable Latch (WEL) bit in the Status Register to a logical “1” state. The WEL bit must be set before a program, erase, Protect Sector,
Unprotect Sector, or Write Status Register command can be executed. This makes the issuance
of these commands a two step process, thereby reducing the chances of a command being
accidentally or erroneously executed. If the WEL bit in the Status Register is not set prior to the
issuance of one of these commands, then the command will not be executed.
AT25DF041A
9.2Write Disable
To issue the Write Enable command, the
CS pin must first be asserted and the opcode of 06h
must be clocked into the device. No address bytes need to be clocked into the device, and any
data clocked in after the opcode will be ignored. When the
CS pin is deasserted, the WEL bit in
the Status Register will be set to a logical “1”. The complete opcode must be clocked into the
device before the
CS pin is deasserted, and the CS pin must be deasserted on an even byte
boundary (multiples of eight bits); otherwise, the device will abort the operation and the state of
the WEL bit will not change.
Figure 9-1.Write Enable
CS
2310
6754
SCK
OPCODE
SI
SO
00000110
MSB
HIGH-IMPEDANCE
The Write Disable command is used to reset the Write Enable Latch (WEL) bit in the Status Register to the logical “0” state. With the WEL bit reset, all program, erase, Protect Sector, Unprotect
Sector, and Write Status Register commands will not be executed. The Write Disable command
is also used to exit the Sequential Program Mode. Other conditions can also cause the WEL bit
to be reset; for more details, refer to the WEL bit section of the Status Register description.
3668E–DFLASH–11/2012
To issue the Write Disable command, the CS pin must first be asserted and the opcode of 04h
must be clocked into the device. No address bytes need to be clocked into the device, and any
data clocked in after the opcode will be ignored. When the CS pin is deasserted, the WEL bit in
the Status Register will be reset to a logical “0”. The complete opcode must be clocked into the
device before the CS pin is deasserted, and the CS pin must be deasserted on an even byte
boundary (multiples of eight bits); otherwise, the device will abort the operation and the state of
the WEL bit will not change.
15
Figure 9-2.Write Disable
CS
9.3Protect Sector
2310
6754
SCK
OPCODE
SI
SO
00000100
MSB
HIGH-IMPEDANCE
Every physical sector of the device has a corresponding single-bit Sector Protection Register
that is used to control the software protection of a sector. Upon device power-up or after a
device reset, each Sector Protection Register will default to the logical “1” state indicating that all
sectors are protected and cannot be programmed or erased.
Issuing the Protect Sector command to a particular sector address will set the corresponding
Sector Protection Register to the logical “1” state. The following table outlines the two states of
the Sector Protection Registers.
Table 9-1.Sector Protection Register Values
ValueSector Protection Status
0Sector is unprotected and can be programmed and erased.
1Sector is protected and cannot be programmed or erased. This is the default state.
Before the Protect Sector command can be issued, the Write Enable command must have been
previously issued to set the WEL bit in the Status Register to a logical “1”. To issue the Protect
Sector command, the CS pin must first be asserted and the opcode of 36h must be clocked into
the device followed by three address bytes designating any address within the sector to be
locked. Any additional data clocked into the device will be ignored. When the CS pin is deasserted, the Sector Protection Register corresponding to the physical sector addressed by
A23 - A0 will be set to the logical “1” state, and the sector itself will then be protected from
program and erase operations. In addition, the WEL bit in the Status Register will be reset back
to the logical “0” state.
The complete three address bytes must be clocked into the device before the CS pin is deasserted, and the CS pin must be deasserted on an even byte boundary (multiples of eight bits);
otherwise, the device will abort the operation, the state of the Sector Protection Register will be
unchanged, and the WEL bit in the Status Register will be reset to a logical “0”.
As a safeguard against accidental or erroneous protecting or unprotecting of sectors, the Sector
Protection Registers can themselves be locked from updates by using the SPRL (Sector Protection Registers Locked) bit of the Status Register (please refer to the Status Register description
for more details). If the Sector Protection Registers are locked, then any attempts to issue the
Protect Sector command will be ignored, and the device will reset the WEL bit in the Status Register back to a logical “0” and return to the idle state once the CS pin has been deasserted.
16
AT25DF041A
3668E–DFLASH–11/2012
Figure 9-3.Protect Sector
CS
AT25DF041A
9.4Unprotect Sector
Issuing the Unprotect Sector command to a particular sector address will reset the corresponding Sector Protection Register to the logical “0” state (see Table 9-1 for Sector Protection
Register values). Every physical sector of the device has a corresponding single-bit Sector Protection Register that is used to control the software protection of a sector.
Before the Unprotect Sector command can be issued, the Write Enable command must have
been previously issued to set the WEL bit in the Status Register to a logical “1”. To issue the
Unprotect Sector command, the CS pin must first be asserted and the opcode of 39h must be
clocked into the device. After the opcode has been clocked in, the three address bytes designating any address within the sector to be unlocked must be clocked in. Any additional data clocked
into the device after the address bytes will be ignored. When the CS pin is deasserted, the Sector Protection Register corresponding to the sector addressed by A23 - A0 will be reset to the
logical “0” state, and the sector itself will be unprotected. In addition, the WEL bit in the Status
Register will be reset back to the logical “0” state.
SCK
SI
SO
2310
OPCODE
00110110
MSBMSB
HIGH-IMPEDANCE
6754101198123129 3027 2826
ADDRESS BITS A23-A0
AAAAAAAA AA A A
The complete three address bytes must be clocked into the device before the CS pin is deasserted, and the CS pin must be deasserted on an even byte boundary (multiples of eight bits);
otherwise, the device will abort the operation, the state of the Sector Protection Register will be
unchanged, and the WEL bit in the Status Register will be reset to a logical “0”.
As a safeguard against accidental or erroneous locking or unlocking of sectors, the Sector Protection Registers can themselves be locked from updates by using the SPRL (Sector Protection
Registers Locked) bit of the Status Register (please refer to the Status Register description for
more details). If the Sector Protection Registers are locked, then any attempts to issue the
Unprotect Sector command will be ignored, and the device will reset the WEL bit in the Status
Register back to a logical “0” and return to the idle state once the CS pin has been deasserted.
Figure 9-4.Unprotect Sector
CS
SCK
SI
SO
2310
OPCODE
00111001
MSBMSB
HIGH-IMPEDANCE
6754101198123129 3027 2826
ADDRESS BITS A23-A0
AAAAAAAA AA A A
3668E–DFLASH–11/2012
17
9.5Global Protect/Unprotect
The Global Protect and Global Unprotect features can work in conjunction with the Protect Sector and Unprotect Sector functions. For example, a system can globally protect the entire
memory array and then use the Unprotect Sector command to individually unprotect certain sectors and individually reprotect them later by using the Protect Sector command. Likewise, a
system can globally unprotect the entire memory array and then individually protect certain sectors as needed.
Performing a Global Protect or Global Unprotect is accomplished by writing a certain combination of data to the Status Register using the Write Status Register command (see “Write Status
Register” section on page 26 for command execution details). The Write Status Register command is also used to modify the SPRL (Sector Protection Registers Locked) bit to control
hardware and software locking.
To perform a Global Protect, the appropriate
system must write a logical “1” to bits 5, 4, 3, and 2 of the Status Register. Conversely, to perform a Global Unprotect, the same WP and SPRL conditions must be met but the system must
write a logical “0” to bits 5, 4, 3, and 2 of the Status Register. Table 9-2 details the conditions
necessary for a Global Protect or Global Unprotect to be performed.
WP pin and SPRL conditions must be met, and the
18
AT25DF041A
3668E–DFLASH–11/2012
Table 9-2.Valid SPRL and Global Protect/Unprotect Conditions
New
Write Status
Current
WP
State
00
SPRL
Value
Register Data
Bit
76543210
0x0000xx
0x0001xx
0x1110xx
0x1111xx
1x0000xx
1x0001xx
1x1110xx
1x1111xx
Protection Operation
Global Unprotect – all Sector Protection Registers reset to 0
No change to current protection.
No change to current protection.
No change to current protection.
Global Protect – all Sector Protection Registers set to 1
Global Unprotect – all Sector Protection Registers reset to 0
No change to current protection.
No change to current protection.
No change to current protection.
Global Protect – all Sector Protection Registers set to 1
No change to the current protection level. All sectors currently
protected will remain protected and all sectors currently unprotected
will remain unprotected.
AT25DF041A
New
SPRL
Value
0
0
0
0
0
1
1
1
1
1
01xxxxxxxx
0x0000xx
0x0001xx
0x1110xx
0x1111xx
10
1x0000xx
1x0001xx
1x1110xx
1x1111xx
0x0000xx
0x0001xx
0x1110xx
0x1111xx
11
1x0000xx
1x0001xx
1x1110xx
1x1111xx
The Sector Protection Registers are hard-locked and cannot be
changed when the WP pin is LOW and the current state of SPRL is 1.
Therefore, a Global Protect/Unprotect will not occur. In addition, the
SPRL bit cannot be changed (the WP pin must be HIGH in order to
change SPRL back to a 0).
Global Unprotect – all Sector Protection Registers reset to 0
No change to current protection.
No change to current protection.
No change to current protection.
Global Protect – all Sector Protection Registers set to 1
Global Unprotect – all Sector Protection Registers reset to 0
No change to current protection.
No change to current protection.
No change to current protection.
Global Protect – all Sector Protection Registers set to 1
No change to the current protection level. All sectors
currently protected will remain protected, and all sectors
currently unprotected will remain unprotected.
The Sector Protection Registers are soft-locked and cannot
be changed when the current state of SPRL is 1. Therefore,
a Global Protect/Unprotect will not occur. However, the
SPRL bit can be changed back to a 0 from a 1 since the WP
pin is HIGH. To perform a Global Protect/Unprotect, the
Write Status Register command must be issued again after
the SPRL bit has been changed froma1toa0.
0
0
0
0
0
1
1
1
1
1
0
0
0
0
0
1
1
1
1
1
3668E–DFLASH–11/2012
Essentially, if the SPRL bit of the Status Register is in the logical “0” state (Sector Protection
Registers are not locked), then writing a 00h to the Status Register will perform a Global Unprotect without changing the state of the SPRL bit. Similarly, writing a 7Fh to the Status Register will
perform a Global Protect and keep the SPRL bit in the logical “0” state. The SPRL bit can, of
course, be changed to a logical “1” by writing an FFh if software-locking or hardware-locking is
desired along with the Global Protect.
19
If the desire is to only change the SPRL bit without performing a Global Protect or Global Unprotect, then the system can simply write a 0Fh to the Status Register to change the SPRL bit from
a logical “1” to a logical “0” provided the
F0h to change the SPRL bit from a logical “0” to a logical “1” without affecting the current sector
protection status (no changes will be made to the Sector Protection Registers).
When writing to the Status Register, bits 5, 4, 3, and 2 will not actually be modified but will be
decoded by the device for the purposes of the Global Protect and Global Unprotect functions.
Only bit 7, the SPRL bit, will actually be modified. Therefore, when reading the Status Register,
bits 5, 4, 3, and 2 will not reflect the values written to them but will instead indicate the status of
the
WP pin and the sector protection status. Please refer to the “Read Status Register” section
and Table 10-1 on page 23 for details on the Status Register format and what values can be
read for bits 5, 4, 3, and 2.
9.6Read Sector Protection Registers
The Sector Protection Registers can be read to determine the current software protection status
of each sector. Reading the Sector Protection Registers, however, will not determine the status
of the WP pin.
To read the Sector Protection Register for a particular sector, the CS pin must first be asserted
and the opcode of 3Ch must be clocked in. Once the opcode has been clocked in, three address
bytes designating any address within the sector must be clocked in. After the last address byte
has been clocked in, the device will begin outputting data on the SO pin during every subsequent clock cycle. The data being output will be a repeating byte of either FFh or 00h to denote
the value of the appropriate Sector Protection Register.
WP pin is deasserted. Likewise, the system can write an
Table 9-3.Read Sector Protection Register – Output Data
Output DataSector Protection Register Value
00hSector Protection Register value is 0 (sector is unprotected).
FFhSector Protection Register value is 1 (sector is protected).
Deasserting the CS pin will terminate the read operation and put the SO pin into a high-impedance state. The CS pin can be deasserted at any time and does not require that a full byte of
data be read.
In addition to reading the individual Sector Protection Registers, the Software Protection Status
(SWP) bit in the Status Register can be read to determine if all, some, or none of the sectors are
software protected (refer to the “Status Register Commands” on page 23 for more details).
Figure 9-5.Read Sector Protection Register
CS
2310
67541011981237383336353431 3229 3039 40
SCK
SI
SO
OPCODE
00111100
MSBMSB
HIGH-IMPEDANCE
ADDRESS BITS A23-A0
AAAAAAAA A
DATA BYTE
DDDDDDDDDD
MSBMSB
20
AT25DF041A
3668E–DFLASH–11/2012
9.7Protected States and the Write Protect (WP) Pin
The WP pin is not linked to the memory array itself and has no direct effect on the protection status of the memory array. Instead, the WP pin, in conjunction with the SPRL (Sector Protection
Registers Locked) bit in the Status Register, is used to control the hardware locking mechanism
of the device. For hardware locking to be active, two conditions must be met – the WP pin must
be asserted and the SPRL bit must be in the logical “1” state.
When hardware locking is active, the Sector Protection Registers are locked and the SPRL bit
itself is also locked. Therefore, sectors that are protected will be locked in the protected state,
and sectors that are unprotected will be locked in the unprotected state. These states cannot be
changed as long as hardware locking is active, so the Protect Sector, Unprotect Sector, and
Write Status Register commands will be ignored. In order to modify the protection status of a
sector, the
reset back to the logical “0” state using the Write Status Register command. When resetting the
SPRL bit back to a logical “0”, it is not possible to perform a Global Protect or Global Unprotect
at the same time since the Sector Protection Registers remain soft-locked until after the Write
Status Register command has been executed.
If the WP pin is permanently connected to GND, then once the SPRL bit is set to a logical “1”,
the only way to reset the bit back to the logical “0” state is to power-cycle or reset the device.
This allows a system to power-up with all sectors software protected but not hardware locked.
Therefore, sectors can be unprotected and protected as needed and then hardware locked at a
later time by simply setting the SPRL bit in the Status Register.
WP pin must first be deasserted, and the SPRL bit in the Status Register must be
AT25DF041A
When the WP pin is deasserted, or if the WP pin is permanently connected to VCC, the SPRL bit
in the Status Register can still be set to a logical “1” to lock the Sector Protection Registers. This
provides a software locking ability to prevent erroneous Protect Sector or Unprotect Sector commands from being processed. When changing the SPRL bit to a logical “1” from a logical “0”, it is
also possible to perform a Global Protect or Global Unprotect at the same time by writing the
appropriate values into bits 5, 4, 3, and 2 of the Status Register.
Tables 9-4 and 9-5 detail the various protection and locking states of the device.
the Protect and Unprotect Sector
commands. Global Protect and
Unprotect can also be performed.
Locked in current state. Protect
and Unprotect Sector commands
will be ignored. Global Protect and
Unprotect cannot be performed.
Unlocked and modifiable using the
Protect and Unprotect Sector
commands. Global Protect and
Unprotect can also be performed.
Locked in current state. Protect and
Unprotect Sector commands will be
ignored. Global Protect and Unprotect
cannot be performed.
22
AT25DF041A
3668E–DFLASH–11/2012
10. Status Register Commands
10.1Read Status Register
The Status Register can be read to determine the device's ready/busy status, as well as the status of many other functions such as Hardware Locking and Software Protection. The Status
Register can be read at any time, including during an internally self-timed program or erase
operation.
AT25DF041A
To read the Status Register, the
clocked into the device. After the last bit of the opcode has been clocked in, the device will begin
outputting Status Register data on the SO pin during every subsequent clock cycle. After the last
bit (bit 0) of the Status Register has been clocked out, the sequence will repeat itself starting
again with bit 7 as long as the
data in the Status Register is constantly being updated, so each repeating sequence will output
new data.
Deasserting the
CS pin will terminate the Read Status Register operation and put the SO pin
into a high-impedance state. The CS pin can be deasserted at any time and does not require
that a full byte of data be read.
Table 10-1.Status Register Format
(1)
Bit
7SPRLSector Protection Registers LockedR/W
6SPMSequential Program Mode StatusR
5EPEErase/Program ErrorR
4WPPWrite Protect (
NameType
WP) Pin StatusR
CS pin must first be asserted and the opcode of 05h must be
CS pin remains asserted and the SCK pin is being pulsed. The
(2)
Description
0Sector Protection Registers are unlocked (default).
1Sector Protection Registers are locked.
0Byte/Page Programming Mode (default).
1Sequential Programming Mode entered.
0Erase or program operation was successful.
1Erase or program error detected.
WP is asserted.
0
WP is deasserted.
1
All sectors are software unprotected (all Sector
00
Protection Registers are 0).
Some sectors are software protected. Read individual
01
3:2SWPSoftware Protection StatusR
1WELWrite Enable Latch StatusR
0RDY/BSYReady/Busy StatusR
Notes:1. Only bit 7 of the Status Register will be modified when using the Write Status Register command.
2. R/W = Readable and writable
R = Readable only
3668E–DFLASH–11/2012
Sector Protection Registers to determine which
sectors are protected.
10Reserved for future use.
All sectors are software protected (all Sector
11
Protection Registers are 1 – default).
0Device is not write enabled (default).
1Device is write enabled.
0Device is ready.
1Device is busy with an internal operation.
23
10.1.1SPRL Bit
10.1.2SPM Bit
The SPRL bit is used to control whether the Sector Protection Registers can be modified or not.
When the SPRL bit is in the logical “1” state, all Sector Protection Registers are locked and cannot be modified with the Protect Sector and Unprotect Sector commands (the device will ignore
these commands). In addition, the Global Protect and Global Unprotect features cannot be performed. Any sectors that are presently protected will remain protected, and any sectors that are
presently unprotected will remain unprotected.
When the SPRL bit is in the logical “0” state, all Sector Protection Registers are unlocked and
can be modified (the Protect Sector and Unprotect Sector commands, as well as the Global Protect and Global Unprotect features, will be processed as normal). The SPRL bit defaults to the
logical “0” state after a power-up or a device reset.
The SPRL bit can be modified freely whenever the WP pin is deasserted. However, if the WP pin
is asserted, then the SPRL bit may only be changed from a logical “0” (Sector Protection Registers are unlocked) to a logical “1” (Sector Protection Registers are locked). In order to reset the
SPRL bit back to a logical “0” using the Write Status Register command, the WP pin will have to
first be deasserted.
The SPRL bit is the only bit of the Status Register that can be user modified via the Write Status
Register command.
The SPM bit indicates whether the device is in the Byte/Page Program mode or the Sequential
Program Mode. The default state after power-up or device reset is the Byte/Page Program
mode.
10.1.3EPE Bit
10.1.4WPP Bit
10.1.5SWP Bits
The EPE bit indicates whether the last erase or program operation completed successfully or
not. If at least one byte during the erase or program operation did not erase or program properly,
then the EPE bit will be set to the logical “1” state. The EPE bit will not be set if an erase or program operation aborts for any reason such as an attempt to erase or program a protected region
or if the WEL bit is not set prior to an erase or program operation. The EPE bit will be updated
after every erase and program operation.
The WPP bit can be read to determine if the WP pin has been asserted or not.
The SWP bits provide feedback on the software protection status for the device. There are three
possible combinations of the SWP bits that indicate whether none, some, or all of the sectors
have been protected using the Protect Sector command or the Global Protect feature. If the
SWP bits indicate that some of the sectors have been protected, then the individual Sector Protection Registers can be read with the Read Sector Protection Registers command to determine
which sectors are in fact protected.
24
AT25DF041A
3668E–DFLASH–11/2012
10.1.6WEL Bit
AT25DF041A
The WEL bit indicates the current status of the internal Write Enable Latch. When the WEL bit is
in the logical “0” state, the device will not accept any program, erase, Protect Sector, Unprotect
Sector, or Write Status Register commands. The WEL bit defaults to the logical “0” state after a
device power-up or reset. In addition, the WEL bit will be reset to the logical “0” state automatically under the following conditions:
• Write Disable operation completes successfully
• Write Status Register operation completes successfully or aborts
• Protect Sector operation completes successfully or aborts
• Unprotect Sector operation completes successfully or aborts
• Byte/Page Program operation completes successfully or aborts
• Sequential Program Mode reaches highest unprotected memory location
• Sequential Program Mode reaches the end of the memory array
• Sequential Program Mode aborts
• Block Erase operation completes successfully or aborts
• Chip Erase operation completes successfully or aborts
• Hold condition aborts
10.1.7RDY/BSY Bit
If the WEL bit is in the logical “1” state, it will not be reset to a logical “0” if an operation aborts
due to an incomplete or unrecognized opcode being clocked into the device before the CS pin is
deasserted. In order for the WEL bit to be reset when an operation aborts prematurely, the entire
opcode for a program, erase, Protect Sector, Unprotect Sector, or Write Status Register command must have been clocked into the device.
The RDY/BSY bit is used to determine whether or not an internal operation, such as a program
or erase, is in progress. To poll the RDY/BSY bit to detect the completion of a program or erase
cycle, new Status Register data must be continually clocked out of the device until the state of
the RDY/BSY bit changes from a logical “1” to a logical “0”.
Figure 10-1. Read Status Register
CS
2310
67541011981221221720191815 1613 1423 24
SCK
OPCODE
SI
SO
00000101
MSB
HIGH-IMPEDANCE
STATUS REGISTER DATASTATUS REGISTER DATA
DDDDDDDDDD
MSBMSB
DDDDDDDD
MSB
3668E–DFLASH–11/2012
25
10.2Write Status Register
The Write Status Register command is used to modify the SPRL bit of the Status Register
and/or to perform a Global Protect or Global Unprotect operation. Before the Write Status Register command can be issued, the Write Enable command must have been previously issued to
set the WEL bit in the Status Register to a logical “1”.
To issue the Write Status Register command, the
CS pin must first be asserted and the opcode
of 01h must be clocked into the device followed by one byte of data. The one byte of data consists of the SPRL bit value, a don’t care bit, four data bits to denote whether a Global Protect or
Unprotect should be performed, and two additional don’t care bits (see Table 10-2). Any additional data bytes that are sent to the device will be ignored. When the CS pin is deasserted, the
SPRL bit in the Status Register will be modified, and the WEL bit in the Status Register will be
reset back to a logical “0”. The values of bits 5, 4, 3, and 2 and the state of the SPRL bit before
the Write Status Register command was executed (the prior state of the SPRL bit) will determine
whether or not a Global Protect or Global Unprotect will be perfomed. Please refer to the “Global
Protect/Unprotect” section on page 18 for more details.
The complete one byte of data must be clocked into the device before the CS pin is deasserted;
otherwise, the device will abort the operation, the state of the SPRL bit will not change, no
potential Global Protect or Unprotect will be performed, and the WEL bit in the Status Register
will be reset back to the logical “0” state.
If the WP pin is asserted, then the SPRL bit can only be set to a logical “1”. If an attempt is made
to reset the SPRL bit to a logical “0” while the WP pin is asserted, then the Write Status Register
command will be ignored, and the WEL bit in the Status Register will be reset back to the logical
“0” state. In order to reset the SPRL bit to a logical “0”, the WP pin must be deasserted.
Table 10-2.Write Status Register Format
Bit 7Bit 6Bit 5Bit 4Bit 3Bit 2Bit 1Bit 0
SPRLXGlobal Protect/UnprotectXX
26
Figure 10-2. Write Status Register
AT25DF041A
CS
SCK
SI
SO
2310
OPCODE
0000000
MSB
HIGH-IMPEDANCE
675410119814151312
STATUS REGISTER IN
1DXDDDDXX
MSB
3668E–DFLASH–11/2012
11. Other Commands and Functions
11.1Read Manufacturer and Device ID
Identification information can be read from the device to enable systems to electronically query
and identify the device while it is in system. The identification method and the command opcode
comply with the JEDEC standard for “Manufacturer and Device ID Read Methodology for SPI
Compatible Serial Interface Memory Devices”. The type of information that can be read from the
device includes the JEDEC defined Manufacturer ID, the vendor specific Device ID, and the vendor specific Extended Device Information.
AT25DF041A
To read the identification information, the
must be clocked into the device. After the opcode has been clocked in, the device will begin outputting the identification data on the SO pin during the subsequent clock cycles. The first byte
that will be output will be the Manufacturer ID followed by two bytes of Device ID information.
The fourth byte output will be the Extended Device Information String Length, which will be 00h
indicating that no Extended Device Information follows. After the Extended Device Information
String Length byte is output, the SO pin will go into a high-impedance state; therefore, additional
clock cycles will have no affect on the SO pin and no data will be output. As indicated in the
JEDEC standard, reading the Extended Device Information String Length and any subsequent
data is optional.
Deasserting the CS pin will terminate the Manufacturer and Device ID read operation and put
the SO pin into a high-impedance state. The CS pin can be deasserted at any time and does not
require that a full byte of data be read.
Table 11-1.Manufacturer and Device ID Information
Byte No.Data TypeValue
1Manufacturer ID1Fh
2Device ID (Part 1)44h
3Device ID (Part 2)01h
4Extended Device Information String Length00h
CS pin must first be asserted and the opcode of 9Fh
Table 11-2.Manufacturer and Device ID Details
Data TypeBit 7Bit 6Bit 5Bit 4Bit 3Bit 2Bit 1Bit 0
JEDEC Assigned Code
Manufacturer ID
00011111
Family CodeDensity Code
Device ID (Part 1)
01000100
Sub CodeProduct Version Code
Device ID (Part 2)
00000001
3668E–DFLASH–11/2012
Hex
ValueDetails
1FhJEDEC Code:0001 1111 (1Fh for Adesto®)
Family Code:010 (AT25/26DFxxx series)
44h
Density Code:00100 (4-Mbit)
Sub Code:000 (Standard series)
01h
Product Version: 00001 (First major revision)
27
Figure 11-1. Read Manufacturer and Device ID
CS
6 0
8 7 38
14 16 15 22 24 23 30 32 31
SCK
OPCODE
11.2Deep Power-down
During normal operation, the device will be placed in the standby mode to consume less power
as long as the CS pin remains deasserted and no internal operation is in progress. The Deep
Power-down command offers the ability to place the device into an even lower power consumption state called the Deep Power-down mode.
When the device is in the Deep Power-down mode, all commands including the Read Status
Register command will be ignored with the exception of the Resume from Deep Power-down
command. Since all commands will be ignored, the mode can be used as an extra protection
mechanism against program and erase operations.
Entering the Deep Power-down mode is accomplished by simply asserting the CS pin, clocking
in the opcode of B9h, and then deasserting the CS pin. Any additional data clocked into the
device after the opcode will be ignored. When the CS pin is deasserted, the device will enter the
Deep Power-down mode within the maximum time of t
The complete opcode must be clocked in before the CS pin is deasserted, and the CS pin must
be deasserted on an even byte boundary (multiples of eight bits); otherwise, the device will abort
the operation and return to the standby mode once the CS pin is deasserted. In addition, the
device will default to the standby mode after a power-cycle or a device reset.
SI
SO
HIGH-IMPEDANCE
Note: Each transition shown for SI and SO represents one byte (8 bits)
9Fh
1Fh 44h 01h 00h
MANUFACTURER ID DEVICE ID
BYTE 1
EDPD
.
DEVICE ID
BYTE 2
EXTENDED
DEVICE
INFORMATION
STRING LENGTH
28
The Deep Power-down command will be ignored if an internally self-timed operation such as a
program or erase cycle is in progress. The Deep Power-down command must be reissued after
the internally self-timed operation has been completed in order for the device to enter the Deep
Power-down mode.
AT25DF041A
3668E–DFLASH–11/2012
Figure 11-2. Deep Power-down
AT25DF041A
CS
SCK
SI
SO
I
CC
11.3Resume from Deep Power-down
In order exit the Deep Power-down mode and resume normal device operation, the Resume
from Deep Power-down command must be issued. The Resume from Deep Power-down command is the only command that the device will recognize while in the Deep Power-down mode.
To resume from the Deep Power-down mode, the CS pin must first be asserted and opcode of
ABh must be clocked into the device. Any additional data clocked into the device after the
opcode will be ignored. When the CS pin is deasserted, the device will exit the Deep Powerdown mode within the maximum time of t
has returned to the standby mode, normal command operations such as Read Array can be
resumed.
2310
OPCODE
10111001
MSB
HIGH-IMPEDANCE
Active Current
Standby Mode Current
RDPD
t
EDPD
6754
Deep Power-Down Mode Current
and return to the standby mode. After the device
If the complete opcode is not clocked in before the CS pin is deasserted, or if the CS pin is not
deasserted on an even byte boundary (multiples of eight bits), then the device will abort the
operation and return to the Deep Power-down mode.
Figure 11-3. Resume from Deep Power-down
CS
t
RDPD
2310
6754
SCK
OPCODE
SI
SO
I
CC
10101011
MSB
HIGH-IMPEDANCE
Active Current
Deep Power-Down Mode Current
Standby Mode Current
3668E–DFLASH–11/2012
29
11.4Hold
The HOLD pin is used to pause the serial communication with the device without having to stop
or reset the clock sequence. The Hold mode, however, does not have an affect on any internally
self-timed operations such as a program or erase cycle. Therefore, if an erase cycle is in progress, asserting the HOLD pin will not pause the operation, and the erase cycle will continue until
it is finished.
Figure 11-4. Hold Mode
CS
SCK
The Hold mode can only be entered while the
simply by asserting the
the SCK high pulse, then the Hold mode won't be started until the beginning of the next SCK low
pulse. The device will remain in the Hold mode as long as the
asserted.
While in the Hold mode, the SO pin will be in a high-impedance state. In addition, both the SI pin
and the SCK pin will be ignored. The WP pin, however, can still be asserted or deasserted while
in the Hold mode.
To end the Hold mode and resume serial communication, the HOLD pin must be deasserted
during the SCK low pulse. If the HOLD pin is deasserted during the SCK high pulse, then the
Hold mode won't end until the beginning of the next SCK low pulse.
If the CS pin is deasserted while the HOLD pin is still asserted, then any operation that may
have been started will be aborted, and the device will reset the WEL bit in the Status Register
back to the logical “0” state.
HOLD pin during the SCK low pulse. If the HOLD pin is asserted during
CS pin is asserted. The Hold mode is activated
HOLD pin and CS pin are
30
HOLD
HoldHoldHold
AT25DF041A
3668E–DFLASH–11/2012
AT25DF041A
12. Electrical Specifications
12.1Absolute Maximum Ratings*
Temperature under Bias ................................ -55C to +125C
Storage Temperature..................................... -65C to +150C
All Input Voltages
(including NC Pins)
with Respect to Ground .....................................-0.6V to +4.1V
All Output Voltages
with Respect to Ground .............................-0.6V to V
CC
+ 0.5V
12.2DC and AC Operating Range
Operating Temperature (Case)Ind.-40Cto85C-40Cto85C
Power Supply2.3V to 3.6V2.7V to 3.6V
V
CC
12.3DC Characteristics
SymbolParameterConditionMinTypMaxUnits
I
SB
Standby Current
CS, WP, HOLD = VCC,
all inputs at CMOS levels
*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.
AT25DF041A (2.3V version)AT25DF041A
2535µA
I
DPD
I
CC1
I
CC2
I
CC3
I
LI
I
LO
V
V
V
V
IL
IH
OL
OH
Deep Power-down Current
Active Current, Read Operation
CS, WP, HOLD = VCC,
all inputs at CMOS levels
f = 70 MHz; I
OUT
= 0 mA;
CS = VIL,VCC= Max
f = 66 MHz; I
OUT
= 0 mA;
CS = VIL,VCC= Max
f = 50 MHz; I
OUT
= 0 mA;
CS = VIL,VCC= Max
f = 33 MHz; I
OUT
= 0 mA;
CS = VIL,VCC= Max
f = 20 MHz; I
OUT
= 0 mA;
CS = VIL,VCC= Max
1520µA
1116
1015
914
mA
812
710
Active Current, Program OperationCS = VCC,VCC= Max1218mA
Active Current, Erase OperationCS = VCC,VCC= Max1420mA
Input Leakage CurrentVIN= CMOS levels1µA
Output Leakage CurrentV
Input Low Voltage0.3 x V
Input High Voltage0.7 x V
= CMOS levels1µA
OUT
CC
CC
V
V
Output Low VoltageIOL= 1.6 mA; VCC=Min0.4V
Output High VoltageIOH= -100 µAVCC-0.2VV
3668E–DFLASH–11/2012
31
12.4AC Characteristics
AT25DF041A
(2.3V version)AT25DF041A
SymbolParameter
f
SCK
f
RDLF
t
SCKH
t
SCKL
t
SCKR
t
SCKF
t
CSH
t
CSLS
t
CSLH
t
CSHS
t
CSHH
t
DS
t
DH
t
DIS
(2)
t
V
t
OH
t
HLS
t
HLH
t
HHS
t
HHH
t
HLQZ
t
HHQX
t
WPS
t
WPH
t
SECP
t
SECUP
t
EDPD
t
RDPD
(1)
Serial Clock (SCK) Frequency5070MHz
SCK Frequency for Read Array (Low Frequency - 03h opcode)3333MHz
SCK High Time8.06.4ns
SCK Low Time8.06.4ns
(1)
SCK Rise Time, Peak-to-Peak (Slew Rate)0.10.1V/ns
(1)
SCK Fall Time, Peak-to-Peak (Slew Rate)0.10.1V/ns
Chip Select High Time5050ns
Chip Select Low Setup Time (relative to SCK)55ns
Chip Select Low Hold Time (relative to SCK)55ns
Chip Select High Setup Time (relative to SCK)55ns
Chip Select High Hold Time (relative to SCK)55ns
Data In Setup Time22ns
Data In Hold Time33ns
Output Disable Time76ns
Output Valid Time76ns
Output Hold Time00ns
HOLD Low Setup Time (relative to SCK)55ns
HOLD Low Hold Time (relative to SCK)55ns
HOLD High Setup Time (relative to SCK)55ns
HOLD High Hold Time (relative to SCK)55ns
(1)
HOLD Low to Output High-Z76ns
(1)
HOLD High to Output Low-Z76ns
(1)(3)
Write Protect Setup Time2020ns
(1)(3)
Write Protect Hold Time100100ns
(1)
Sector Protect Time (from Chip Select High)2020ns
(1)
Sector Unprotect Time (from Chip Select High)2020ns
(1)
Chip Select High to Deep Power-down33µs
(1)
Chip Select High to Standby Mode33µs
Notes:1. Not 100% tested (value guaranteed by design and characterization).
2. 15 pF load at 70 MHz, 30 pF load at 66 MHz.
3. Only applicable as a constraint for the Write Status Register command when SPRL = 1
MinMaxMinMaxUnits
32
AT25DF041A
3668E–DFLASH–11/2012
AT25DF041A
12.5Program and Erase Characteristics
SymbolParameterMinTypMaxUnits
(1)
t
PP
t
BP
(1)
t
BLKE
(1)(2)
t
CHPE
(2)
t
WRSR
Note:1. Maximum values indicate worst-case performance after 100,000 erase/program cycles.
12.6Power-up Conditions
SymbolParameterMinMaxUnits
t
VCSL
t
PUW
V
POR
Page Program Time (256 Bytes)1.25ms
Byte Program Time7µs
4 Kbytes50200
Block Erase Time
64 Kbytes400950
Chip Erase Time37sec
Write Status Register Time200ns
2. Not 100% tested (value guaranteed by design and characterization).
Minimum VCCto Chip Select Low Time70µs
Power-up Device Delay Before Program or Erase Allowed10ms
Power-on Reset Voltage1.52.2V
ms32 Kbytes250600
12.7Input Test Waveforms and Measurement Levels
AC
DRIVING
LEVELS
tR,tF< 2 ns (10% to 90%)
2.4V
0.45V
12.8Output Test Load
DEVICE
UNDER
TEST
1.5V
AC
MEASUREMENT
LEVEL
30 pF
3668E–DFLASH–11/2012
33
13. Waveforms
Figure 13-1. Serial Input Timing
CS
t
CSLS
SCK
t
SCKH
t
SCKL
t
CSLH
t
t
CSHS
CSH
t
CSHH
t
DS
SI
SO
HIGH-IMPEDANCE
MSB
Figure 13-2. Serial Output Timing
CS
SCK
SI
t
V
SO
Figure 13-3.
HOLD Timing – Serial Input
t
DH
MSBLSB
t
SCKH
t
OH
t
V
t
SCKL
t
DIS
34
CS
SCK
HOLD
SI
SO
HIGH-IMPEDANCE
AT25DF041A
t
HHH
t
HLS
t
HLH
t
HHS
3668E–DFLASH–11/2012
Figure 13-4. HOLD Timing – Serial Output
CS
SCK
t
HHH
HOLD
SI
t
HLS
t
HLH
t
HHS
AT25DF041A
t
HLQZ
t
HHQX
SO
Figure 13-5. WP Timing for Write Status Register Command When SPRL = 1
Adesto®, the Adesto logo, CBRAM®, and DataFlash® are registered trademarks or trademarks of Adesto Technologies. All other marks are the property of their respective
owners.
Disclaimer: The information in this document is provided in connection with Adesto products. No license, express or implied, by estoppel or otherwise, to any intellectual property right is granted by this
document or in connection with the sale of Adesto products. EXCEPT AS SET FORTH IN THE ADESTO TERMS AND CONDITIONS OF SALES LOCATED ON THE ADESTO WEBSITE, ADESTO
ASSUMES NO LIABILITY WHATSOEVER AND DISCLAIMS ANY EXPRESS, IMPLIED OR STATUTORY WARRANTY RELATING TO ITS PRODUCTS INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. IN NO EVENT SHALL ADESTO BE LIABLE FOR ANY DIRECT, INDIRECT,
CONSEQUENTIAL, PUNITIVE, SPECIAL OR INCIDENTAL DAMAGES (INCLUDING, WITHOUT LIMITATION, DAMAGES FOR LOSS AND PROFITS, BUSINESS INTERRUPTION, OR LOSS OF
INFORMATION) ARISING OUT OF THE USE OR INABILITY TO USE THIS DOCUMENT, EVEN IF ADESTO HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. Adesto makes no
representations or warranties with respect to the accuracy or completeness of the contents of this document and reserves the right to make changes to specifications and products descriptions at any time
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