View detail for AT26F004

Features
• Single 2.7V - 3.6V Supply
• Serial Peripheral Interface (SPI) Compatible
– Supports SPI Modes 0 and 3
• 33 MHz Maximum Clock Frequency
• Flexible, Uniform Erase Architecture
•
•
•
•
•
•
•
•
•
•
– 4-Kbyte Blocks
– 32-Kbyte Blocks
– 64-Kbyte Blocks
– Full Chip Erase
Optimized Physical Sectoring for Code Shadowing and Code + Data Storage
Applications
– One 16-Kbyte Top Boot Sector
– Two 8-Kbyte Sectors
– One 32-Kbyte Sector
– Seven 64-Kbyte Sectors
Individual Sector Protection for Program/Erase Protection
Hardware Controlled Locking of Protected Sectors
Byte Program Architecture with Sequential Byte Program Mode Capability
– Sequential Byte Program Mode Improves Throughput for
Programming Multiple Bytes
JEDEC Standard Manufacturer and Device ID Read Methodology
Low Power Dissipation
– 7 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
– 8-lead SOIC (150-mil and 208-mil wide)
– 8-pad MLF (6 x 5 x 1.00 mm)
4-megabit
2.7-volt Only
Serial Firmware
DataFlash®
Memory
AT26F004
For New
Designs Use
AT25DF041A
1. Description
The AT26F004 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 AT26F004, 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.
The physical sectoring and the erase block sizes of the AT26F004 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.
3588D–DFLASH–10/08
The AT26F004 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.
Specifically designed for use in 3-volt systems, the AT26F004 supports read, program, and
erase operations with a supply voltage range of 2.7V to 3.6V. No separate voltage is required for
programming and erasing.
2. Pin Descriptions and Pinouts
Table 2-1.
Asserted
State
Type
CS
CHIP SELECT: Asserting the CS pin selects the device. When the CS pin is deasserted, the
device will be deselected and normally 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 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.
Low
Input
SCK
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.
–
Input
SI
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.
–
Input
SO
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.
–
Output
WP
WRITE PROTECT: The WP pin controls the hardware locking feature of the device. Refer to
section “Protection Commands and Features” on page 13 for more details on protection features
and the WP pin.
The WP pin is not internally pulled-high and cannot be left floating. If hardware controlled locking
will not be used, then the WP pin must be externally connected to VCC.
Low
Input
HOLD
HOLD: The HOLD pin is used to temporarily pause serial communication without deselecting
or resetting the device. While the HOLD pin is asserted, transitions on the SCK pin and data on 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 27 for additional details on the Hold operation.
The HOLD pin is not internally pulled-high and cannot be left floating. If the Hold function will not
be used, then the HOLD pin must be externally connected to VCC.
Low
Input
Symbol
2
Pin Descriptions
Name and Function
VCC
DEVICE POWER SUPPLY: The VCC pin is used to supply the source voltage to the device.
Operations at invalid VCC voltages may produce spurious results and should not be attempted.
–
Power
GND
GROUND: The ground reference for the power supply. GND should be connected to the
system ground.
–
Power
AT26F004
3588D–DFLASH–10/08
AT26F004
Figure 2-1.
8-SOIC Top View
CS
SO
WP
GND
1
2
3
4
Figure 2-2.
8
7
6
5
8-MLF Top View
CS
SO
WP
GND
VCC
HOLD
SCK
SI
1
8
2
7
3
6
4
5
VCC
HOLD
SCK
SI
3. Block Diagram
CS
CONTROL LOGIC
I/O BUFFERS
AND LATCHES
INTERFACE
CONTROL
AND
LOGIC
SI
SO
WP
HOLD
ADDRESS LATCH
SCK
Y-DECODER
Y-GATING
X-DECODER
FLASH
MEMORY
ARRAY
4. Memory Array
To provide the greatest flexibility, the memory array of the AT26F004 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. The
Memory Architecture Diagram illustrates the breakdown of each erase level as well as the
breakdown of each physical sector.
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3588D–DFLASH–10/08
Figure 4-1.
Memory Architecture Diagram
Block Erase Detail
64KB
32KB
Block Erase
Block Erase
(D8h Command) (52h Command)
16KB
(Sector 10)
8KB
(Sector 9)
8KB
(Sector 8)
32KB
64KB
32KB
(Sector 7)
32KB
32KB
64KB
(Sector 6)
64KB
•••
•••
•••
32KB
32KB
64KB
(Sector 0)
64KB
32KB
4
4KB
Block Erase
(20h Command)
4KB
4KB
4KB
4KB
4KB
4KB
4KB
4KB
4KB
4KB
4KB
4KB
4KB
4KB
4KB
4KB
4KB
4KB
4KB
4KB
4KB
4KB
4KB
4KB
4KB
4KB
4KB
4KB
4KB
4KB
4KB
4KB
Block Address
Range
7FFFFh
7EFFFh
7DFFFh
7CFFFh
7BFFFh
7AFFFh
79FFFh
78FFFh
77FFFh
76FFFh
75FFFh
74FFFh
73FFFh
72FFFh
71FFFh
70FFFh
6FFFFh
6EFFFh
6DFFFh
6CFFFh
6BFFFh
6AFFFh
69FFFh
68FFFh
67FFFh
66FFFh
65FFFh
64FFFh
63FFFh
62FFFh
61FFFh
60FFFh
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
7F000h
7E000h
7D000h
7C000h
7B000h
7A000h
79000h
78000h
77000h
76000h
75000h
74000h
73000h
72000h
71000h
70000h
6F000h
6E000h
6D000h
6C000h
6B000h
6A000h
69000h
68000h
67000h
66000h
65000h
64000h
63000h
62000h
61000h
60000h
0FFFFh
0EFFFh
0DFFFh
0CFFFh
0BFFFh
0AFFFh
09FFFh
08FFFh
07FFFh
06FFFh
05FFFh
04FFFh
03FFFh
02FFFh
01FFFh
00FFFh
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
0F000h
0E000h
0D000h
0C000h
0B000h
0A000h
09000h
08000h
07000h
06000h
05000h
04000h
03000h
02000h
01000h
00000h
•••
Internal Sectoring for
Sector Protection
Function
4KB
4KB
4KB
4KB
4KB
4KB
4KB
4KB
4KB
4KB
4KB
4KB
4KB
4KB
4KB
4KB
AT26F004
3588D–DFLASH–10/08
AT26F004
5. Device Operation
The AT26F004 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 AT26F004 via the
SPI bus which is comprised of four signal lines: Chip Select (CS), Serial Clock (SCK), Serial
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 AT26F004 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
SI
MSB
SO
LSB
MSB
LSB
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 AT26F004 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 CS pin is deasserted before all eight bits of an opcode are sent to the device, then 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 AT26F004 memory array is
07FFFFh, address bits A23 - A19 are always ignored by the device.
5
3588D–DFLASH–10/08
Table 6-1.
Command Listing
Command
Opcode
Address
Bytes
Dummy
Bytes
Data Bytes
Read Commands
Read Array
0Bh
0000 1011
3
1
1+
Read Array (Low Frequency)
03h
0000 0011
3
0
1+
Block Erase (4 KBytes)
20h
0010 0000
3
0
0
Block Erase (32 KBytes)
52h
0101 0010
3
0
0
Block Erase (64 KBytes)
D8h
1101 1000
3
0
0
60h
0110 0000
0
0
0
C7h
1100 0111
0
0
0
02h
0000 0010
3
0
1
0
1
Program and Erase Commands
Chip Erase
Byte Program
Sequential Byte Program Mode
(1)
AFh
1010 1111
3, 0
Write Enable
06h
0000 0110
0
0
0
Write Disable
04h
0000 0100
0
0
0
Protect Sector
36h
0011 0110
3
0
0
Unprotect Sector
39h
0011 1001
3
0
0
Read Sector Protection Registers
3Ch
0011 1100
3
0
1+
Read Status Register
05h
0000 0101
0
0
1+
Write Status Register
01h
0000 0001
0
0
1
Read Manufacturer and Device ID
9Fh
1001 1111
0
0
1 to 4
Deep Power-down
B9h
1011 1001
0
0
0
Resume from Deep Power-down
ABh
1010 1011
0
0
0
Protection Commands
Status Register Commands
Miscellaneous Commands
Notes:
6
1. Three address bytes are only required for the first operation to designate the address at which to start the programming.
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.
AT26F004
3588D–DFLASH–10/08
AT26F004
7. Read Commands
7.1
Read 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 fSCK. The 03h
opcode can be used for lower frequency read operations up to the maximum specified by fRDLF.
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.
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.
Figure 7-1.
Read Array - 0Bh Opcode
CS
0
1
2
3
4
5
6
7
8
9
10 11 12
29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48
SCK
OPCODE
SI
0
0
0
0
1
ADDRESS BITS A23-A0
0
1
A
1
MSB
A
A
A
A
A
A
DON'T CARE
A
A
MSB
X
X
X
X
X
X
X
X
MSB
DATA BYTE 1
HIGH-IMPEDANCE
SO
D
D
D
D
D
D
D
D
MSB
Figure 7-2.
D
D
MSB
Read Array - 03h Opcode
CS
0
1
2
3
4
5
6
7
8
9
10 11 12
29 30 31 32 33 34 35 36 37 38 39 40
SCK
OPCODE
SI
0
0
0
0
0
ADDRESS BITS A23-A0
0
MSB
1
1
A
A
A
A
A
A
A
A
A
MSB
DATA BYTE 1
SO
HIGH-IMPEDANCE
D
MSB
D
D
D
D
D
D
D
D
D
MSB
7
3588D–DFLASH–10/08
8. Program and Erase Commands
8.1
Byte Program
The Byte Program command allows a single byte of data to be programmed into a previously
erased memory location. 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 Program command can be started, the Write
Enable command must have been previously issued to the device (see “Write Enable” on page
13) to set the Write Enable Latch (WEL) bit of the Status Register to a logical “1” state.
To perform a Byte Program command, an opcode of 02h must be clocked into the device followed by the three address bytes denoting which byte location of the memory array to program.
After the address bytes have been clocked in, the next byte of data clocked into the device will
be latched internally. If more than one byte of data is clocked in, then only the first byte of data
sent on the SI pin will be stored in the internal latches and all subsequent bytes will be ignored.
When the CS pin is deasserted, the device will take the one byte stored in the internal latches
and program it into the memory array location specified by A23 - A0. The programming of the
byte is internally self-timed and should take place in a time of tBP. The three address bytes and a
complete byte of data must be clocked into the device before the CS pin is deasserted; 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 “Protect Sector” on page 15), then the Byte 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 tBP time to determine if the byte has 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 Byte Program mode is the default programming mode after the device powers-up or
resumes from a device reset.
Figure 8-1.
Byte Program
CS
0
1
2
3
4
5
6
7
8
9
10 11 12
29 30 31 32 33 34 35 36 37 38 39
SCK
OPCODE
SI
0
0
0
0
0
ADDRESS BITS A23-A0
0
MSB
SO
8
1
0
A
MSB
A
A
A
A
A
A
DATA IN
A
A
D
D
D
D
D
D
D
D
MSB
HIGH-IMPEDANCE
AT26F004
3588D–DFLASH–10/08
AT26F004
8.2
Sequential Byte Program Mode
The Sequential Byte Program mode improves throughput over the single Byte Program operation when programming multiple bytes of data into consecutive address locations. When using
the Sequential Byte Programming mode, an internal address counter 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. All address locations to be programmed using the Sequential Byte
Program mode must be in the erased state. Before the Sequential Byte 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 Byte Program mode, the CS pin must first be asserted, and the opcode
of 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 next byte of data clocked into the device will be latched internally. Deasserting the CS pin will start the internally self-timed program operation, and the first
byte 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 AFh opcode, and then clocking in the next byte of
data. When the CS pin is deasserted, the second byte of data will be programmed into 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 Byte Program mode has
been entered.
When the last desired byte has been programmed into the memory array, the Sequential Byte
Program mode operation can be terminated by reasserting the CS pin and sending 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 first
byte of data sent on the SI pin will be stored in the internal latches and all subsequent bytes will
be ignored. 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; 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.
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 Byte 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 Byte Program mode. Therefore, when
the last byte (07FFFFh) of the memory array has been programmed, the device will automatically exit the Sequential Byte Program mode and reset the WEL bit in the Status Register back
to the logical “0” state. In addition, the Sequential Byte 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 Byte
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 Byte Program mode would automatically end. To continue programming with Sector 2, the Sequential Byte Program mode would have to be restarted by
supplying the AFh opcode, the three address bytes, and the first byte of Sector 2 to program.
9
3588D–DFLASH–10/08
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 tBP time to determine if the byte has finished programming before starting the next Sequential Byte Program mode cycle.
Figure 8-2.
Sequential Byte Program Mode – Status Register Polling
CS
Seqeuntial Program Mode
Command
SI
AFh
A23-16
Status Register Read Seqeuntial Program Mode
Command
Command
A15-8
A7-0
Data
05h
AFh
Data
Seqeuntial Program Mode Write Disable
Command
Command
05h
AFh
Data
04h
05h
First Address to Program
STATUS REGISTER
DATA
STATUS REGISTER
DATA
STATUS REGISTER
DATA
HIGH-IMPEDANCE
SO
Note: Each transition
Figure 8-3.
shown for SI represents one byte (8 bits)
Sequential Byte Program Mode – Waiting Maximum Byte Program Time
CS
tBP
Seqeuntial Program Mode
Command
SI
AFh
A23-16
A15-8
A7-0
Data
tBP
tBP
Seqeuntial Program Mode
Command
Seqeuntial Program Mode
Command
Write Disable
Command
AFh
AFh
04h
Data
Data
First Address to Program
SO
HIGH-IMPEDANCE
Note: Each transition
10
shown for SI represents one byte (8 bits)
AT26F004
3588D–DFLASH–10/08
AT26F004
8.3
Block Erase
A block of 4 Kbytes, 32 Kbytes, 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-Kbyte, 32-Kbyte, 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 self-timed and should take place in a time of tBLKE.
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; otherwise, the device will abort the operation and no erase operation will be performed.
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 CS pin has been deasserted. In addition, with the larger Block Erase
sizes of 32 Kbytes and 64 Kbytes, more than one physical sector may be erased (e.g. sectors
10, 9 and 8) 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 tBLKE time to determine if the device has finished erasing. At
some point before the erase cycle completes, the WEL bit in the Status Register will be reset
back to the logical “0” state.
Figure 8-4.
Block Erase
CS
0
1
2
3
4
5
6
7
8
9
10 11 12
26 27 28 29 30 31
SCK
OPCODE
SI
C
C
C
C
C
C
MSB
SO
ADDRESS BITS A23-A0
C
C
A
A
A
A
A
A
A
A
A
A
A
A
MSB
HIGH-IMPEDANCE
11
3588D–DFLASH–10/08
8.4
Chip 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 tCHPE.
The complete opcode must be clocked into the device before the CS pin is deasserted; 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 tCHPE time to determine if the device has finished erasing. At
some point before the erase cycle completes, the WEL bit in the Status Register will be reset
back to the logical “0” state.
Figure 8-5.
Chip Erase
CS
0
1
2
3
4
5
6
7
SCK
OPCODE
SI
C
C
C
C
C
C
C
C
MSB
SO
12
HIGH-IMPEDANCE
AT26F004
3588D–DFLASH–10/08
AT26F004
9. Protection Commands and Features
9.1
Write 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.
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; otherwise, the device will abort the operation and the
state of the WEL bit will not change.
Figure 9-1.
Write Enable
CS
0
1
2
3
4
5
6
7
SCK
OPCODE
SI
0
0
0
0
0
1
1
0
MSB
SO
HIGH-IMPEDANCE
13
3588D–DFLASH–10/08
9.2
Write Disable
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” on page 20.
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; otherwise, the device will abort the operation and the
state of the WEL bit will not change.
Figure 9-2.
Write Disable
CS
0
1
2
3
4
5
6
7
SCK
OPCODE
SI
0
0
0
0
0
1
0
0
MSB
SO
14
HIGH-IMPEDANCE
AT26F004
3588D–DFLASH–10/08
AT26F004
9.3
Protect Sector
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
Value
Sector Protection Status
0
Sector is unprotected and can be programmed and erased.
1
Sector 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; 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 (refer to “Status Register Commands” on page
19 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.
Figure 9-3.
Protect Sector
CS
0
1
2
3
4
5
6
7
8
9
10 11 12
26 27 28 29 30 31
SCK
OPCODE
SI
0
0
1
1
0
ADDRESS BITS A23-A0
1
MSB
SO
1
0
A
A
A
A
A
A
A
A
A
A
A
A
MSB
HIGH-IMPEDANCE
15
3588D–DFLASH–10/08
9.4
Unprotect 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.
The complete three address bytes must be clocked into the device before the CS pin is deasserted; 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 (refer to “Status Register Commands” on page 19
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
0
1
2
3
4
5
6
7
8
9
10 11 12
26 27 28 29 30 31
SCK
OPCODE
SI
0
0
1
1
1
ADDRESS BITS A23-A0
0
MSB
SO
16
0
1
A
A
A
A
A
A
A
A
A
A
A
A
MSB
HIGH-IMPEDANCE
AT26F004
3588D–DFLASH–10/08
AT26F004
9.5
Read 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.
Table 9-2.
Output Data
Read Sector Protection Register – Output Data
Sector Protection Register Value
00h
Sector Protection Register value is 0 (sector is unprotected).
FFh
Sector 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 “Status Register Commands” on page 19 for more details).
Figure 9-5.
Read Sector Protection Register
CS
0
1
2
3
4
5
6
7
8
9
10 11 12
29 30 31 32 33 34 35 36 37 38 39 40
SCK
OPCODE
SI
0
0
1
1
1
ADDRESS BITS A23-A0
1
MSB
0
0
A
A
A
A
A
A
A
A
A
MSB
DATA BYTE
SO
HIGH-IMPEDANCE
D
MSB
D
D
D
D
D
D
D
D
D
MSB
17
3588D–DFLASH–10/08
9.6
Protected 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 WP pin must first be deasserted, and the SPRL bit in the Status Register must be
reset back to the logical “0” state.
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.
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.
Tables 9-3 and 9-4 detail the various protection and locking states of the device.
Table 9-3.
Software Protection
WP
Sector Protection Register
n(1)
Sector
n(1)
0
Unprotected
1
Protected
X
(Don't Care)
Note:
1. “n” represents a sector number
Table 9-4.
18
Hardware and Software Locking
WP
SPRL
Locking
SPRL
Sector Protection Registers
0
0
–
Can be modified from
0 to 1
Unlocked and modifiable using the Protect and
Unprotect Sector commands
0
1
Hardware
locked
Locked
Locked in current state. Protect and Unprotect
Sector commands will be ignored.
1
0
–
Can be modified from
0 to 1
Unlocked and modifiable using the Protect and
Unprotect Sector commands
1
1
Software
locked
Can be modified from
1 to 0
Locked in current state. Protect and Unprotect
Sector commands will be ignored.
AT26F004
3588D–DFLASH–10/08
AT26F004
10. Status Register Commands
10.1
Read 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.
To read the Status Register, the CS pin must first be asserted and the opcode of 05h must be
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 CS pin remains asserted and the SCK pin is being pulsed. 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.
Bit
(1)
Status Register Format
Type(2)
Name
Description
7
SPRL
Sector Protection Registers
Locked
R/W
0
1
Sector Protection Registers are unlocked (default).
Sector Protection Registers are locked.
6
SPM
Sequential Program Mode
Status
R
0
1
Byte programming mode (default).
Sequential Programming mode entered.
5
RES
Reserved for future use
R
0
Reserved for future use.
4
WPP
Write Protect (WP) Pin
Status
R
0
1
WP is asserted.
WP is deasserted.
00
01
10
11
All sectors are software unprotected.
Some sectors are software protected. Read Sector Protection
Registers.
Reserved for future use.
All sectors are software protected (default).
3:2
SWP
1
WEL
0
RDY/BSY
Notes:
Software Protection Status
R
Write Enable Latch Status
R
0
1
Device is not write enabled (default).
Device is write enabled.
Ready/Busy Status
R
0
1
Device is ready.
Device is busy with an internal operation.
1. Bit 7 of the Status Register is the only bit that can be user modified
2. R/W = Readable and writable
R = Readable only
19
3588D–DFLASH–10/08
10.1.1
SPRL 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). 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 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 than can be user modified via the Write Status
Register command.
10.1.2
SPM Bit
The SPM bit indicates whether the device is in the Byte Program mode or the Sequential Program mode. The default state after power-up or device reset is the Byte Program mode.
10.1.3
WPP Bit
The WPP bit can be read to determine if the WP pin has been asserted or not.
10.1.4
SWP Bits
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. 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.
10.1.5
WEL Bit
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 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
20
AT26F004
3588D–DFLASH–10/08
AT26F004
• Block Erase operation completes successfully or aborts
• Chip Erase operation completes successfully or aborts
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.
10.1.6
RDY/BSY Bit
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
0
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
SCK
OPCODE
SI
0
0
0
0
0
1
0
1
MSB
STATUS REGISTER DATA
SO
HIGH-IMPEDANCE
D
MSB
D
D
D
D
D
D
D
STATUS REGISTER DATA
D
MSB
D
D
D
D
D
D
D
D
D
MSB
21
3588D–DFLASH–10/08
10.2
Write Status Register
The Write Status Register command is used to modify the SPRL bit of the Status Register.
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. After the opcode has been clocked in, one byte of data
comprised of the SPRL bit value and seven don't care bits must be clocked in. 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 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, 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.
Figure 10-2. Write Status Register
CS
0
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15
SCK
OPCODE
SI
0
0
0
0
0
STATUS REGISTER IN
0
MSB
SO
22
0
1
D
X
X
X
X
X
X
X
MSB
HIGH-IMPEDANCE
AT26F004
3588D–DFLASH–10/08
AT26F004
11. Other Commands and Functions
11.1
Read 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.
To read the identification information, the CS pin must first be asserted and the opcode of 9Fh
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.
Byte No.
Manufacturer and Device ID Information
Data Type
Value
1
Manufacturer ID
1FH
2
Device ID (Part 1)
04H
3
Device ID (Part 2)
00H
4
Extended Device Information String Length
00H
23
3588D–DFLASH–10/08
Table 11-2.
Manufacturer and Device ID Details
Data Type
Manufacturer ID
Device ID (Part 1)
Device ID (Part 2)
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
1
1
JEDEC Assigned Code
0
0
0
1
1
Family Code
0
0
Density Code
0
0
0
MLC Code
0
0
1
1
0
0
Product Version Code
0
0
0
0
0
0
Hex
Value Details
1FH
JEDEC Code:
0001 1111 (1FH for Atmel)
04H
Family Code:
Density Code:
000 (AT26Fxxx series)
00100 (4-Mbit)
00H
MLC Code:
000 (1-bit/cell technology)
Product Version: 00000 (Initial version)
Figure 11-1. Read Manufacturer and Device ID
CS
0
6
7
8
14 15 16
22 23 24
30 31 32
38
SCK
OPCODE
SI
9Fh
HIGH-IMPEDANCE
SO
Note: Each transition
24
1Fh
04h
00h
00h
MANUFACTURER ID
DEVICE ID
BYTE 1
DEVICE ID
BYTE 2
EXTENDED
DEVICE
INFORMATION
STRING LENGTH
shown for SI and SO represents one byte (8 bits)
AT26F004
3588D–DFLASH–10/08
AT26F004
11.2
Deep 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 tEDPD.
The complete opcode must be clocked in before the CS pin is deasserted; 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.
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.
Figure 11-2. Deep Power-down
CS
tEDPD
0
1
2
3
4
5
6
7
SCK
OPCODE
SI
1
0
1
1
1
0
0
1
MSB
SO
HIGH-IMPEDANCE
Active Current
ICC
Standby Mode Current
Deep Power-Down Mode Current
25
3588D–DFLASH–10/08
11.3
Resume 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 tRDPD and return to the standby mode. After the device
has returned to the standby mode, normal command operations such as Read Array can be
resumed.
If the complete opcode is not clocked in before the CS pin is deasserted, then the device will
abort the operation and return to the Deep Power-down mode.
Figure 11-3. Resume from Deep Power-down
CS
tRDPD
0
1
2
3
4
5
6
7
SCK
OPCODE
SI
1
0
1
0
1
0
1
1
MSB
SO
HIGH-IMPEDANCE
Active Current
ICC
Deep Power-Down Mode Current
26
Standby Mode Current
AT26F004
3588D–DFLASH–10/08
AT26F004
11.4
Hold
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.
The Hold mode can only be entered while the CS pin is asserted. The Hold mode is activated
simply by asserting the HOLD pin during the SCK low pulse. If the HOLD pin is asserted during
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 HOLD pin and CS pin are
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 the Hold mode will abort
and the device may abort the current operation depending on whether or not a complete
opcode, address bytes, or data byte was already clocked into the device before the Hold mode
was entered. The WEL bit in the Status Register will be reset back to a logical “0” if a program,
erase, Protect Sector, Unprotect Sector, or Write Status Register operation aborts as a result of
the Hold mode aborting.
Figure 11-4. Hold Mode
CS
SCK
HOLD
Hold
Hold
Hold
27
3588D–DFLASH–10/08
12. Electrical Specifications
12.1
Absolute Maximum Ratings*
Temperature under Bias ............................... -55° C to +125° C
*NOTICE:
Storage Temperature .................................... -65° C to +150° C
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 VCC + 0.5V
12.2
Stresses beyond 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 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.
DC and AC Operating Range
AT26F004
Operating Temperature (Case)
Industrial
-40° C to 85° C
VCC Power Supply
12.3
2.7V to 3.6V
DC Characteristics
Symbol
Parameter
Condition
ISB
Standby Current
IDPD
Deep Power-down Current
ICC1
Active Current, Read Operation
Min
Typ
Max
Units
CS, WP, HOLD = VCC,
all inputs at CMOS levels
25
35
µA
CS, WP, HOLD = VCC,
all inputs at CMOS levels
20
25
µA
f = 33 MHz; IOUT = 0 mA;
CS = VIL, VCC = Max
8
12
f = 20 MHz; IOUT = 0 mA;
CS = VIL, VCC = Max
7
10
mA
ICC2
Active Current, Program Operation
CS = VCC, VCC = Max
9
12
mA
ICC3
Active Current, Erase Operation
CS = VCC, VCC = Max
9
12
mA
ILI
Input Leakage Current
VIN = CMOS levels
1
µA
ILO
Output Leakage Current
VOUT = CMOS levels
1
µA
VIL
Input Low Voltage
0.3 x VCC
V
VIH
Input High Voltage
VOL
Output Low Voltage
IOL = 1.6 mA; VCC = Min
VOH
Output High Voltage
IOH = -100 µA
28
0.7 x VCC
V
0.4
VCC - 0.2V
V
V
AT26F004
3588D–DFLASH–10/08
AT26F004
12.4
AC Characteristics
Symbol
Parameter
fSCK
Max
Units
Serial Clock (SCK) Frequency
33
MHz
fRDLF
SCK Frequency for Read Array (Low Frequency – 03h opcode)
20
MHz
tSCKH
SCK High Time
13
20(1)
ns
tSCKL
SCK Low Time
13
20(1)
ns
tSCKR(2)
SCK Rise Time, Peak-to-Peak (Slew Rate)
0.1
V/ns
tSCKF(2)
SCK Fall Time, Peak-to-Peak (Slew Rate)
0.1
V/ns
tCSH
Chip Select High Time
50
ns
tCSLS
Chip Select Low Setup Time (relative to SCK)
5
ns
tCSLH
Chip Select Low Hold Time (relative to SCK)
5
12(3)
ns
tCSHS
Chip Select High Setup Time (relative to SCK)
5
ns
tCSHH
Chip Select High Hold Time (relative to SCK)
5
ns
tDS
Data In Setup Time
3
ns
tDH
Data In Hold Time
3
ns
tOH
Output Hold Time
0
ns
tDIS(2)
Output Disable Time
tV
Output Valid Time
tHLS
HOLD Low Setup Time (relative to SCK)
5
ns
tHLH
HOLD Low Hold Time (relative to SCK)
5
ns
tHHS
HOLD High Setup Time (relative to SCK)
5
ns
tHHH
HOLD High Hold Time (relative to SCK)
5
ns
tHLQZ(2)
HOLD Low to Output High-Z
9
ns
tHHQX(2)
HOLD High to Output Low-Z
9
ns
tWPS(2)(4)
Write Protect Setup Time
20
ns
Write Protect Hold Time
100
ns
tWPH
(2)(4)
Min
10
ns
12
18(1)
ns
tSECP(2)
Sector Protect Time (from Chip Select High)
20
ns
tSECUP(2)
Sector Unprotect Time (from Chip Select High)
20
ns
tEDPD(2)
Chip Select High to Deep Power-down
3
µs
tRDPD(2)
Chip Select High to Standby Mode
3
µs
Notes:
1. Specification only applies when using the 03h Read Array (Low Frequency) command.
2. Not 100% tested (value guaranteed by design and characterization).
3. Specification only applies when using the SPI Mode 3 timing.
4. Only applicable as a constraint for the Write Status Register command when SPRL = 1.
29
3588D–DFLASH–10/08
12.5
Program and Erase Characteristics
Symbol
Parameter
tBP
Byte Program Time
tPP
Page Program Time (256 Bytes Using Sequential Program Mode)
tBLKE
Units
µs
ms
4-Kbyte
0.1
0.35
32-Kbyte
0.38
0.65
64-Kbyte
0.75
1.0
6
10
sec.
200
ns
Write Status Register Time
Note:
1. Not 100% tested (value guaranteed by design and characterization).
12.6
Power-Up Conditions
Parameter
Min
Minimum VCC to Chip Select Low Time
Max
50
Power-up Device Delay Before Program or Erase Allowed
Power-on Reset Voltage
12.7
Max
5
Chip Erase Time
(1)
Typ
15
Block Erase Time
tCHPE
tWRSR
Min
1.5
sec.
Units
µs
10
ms
2.5
V
Input Test Waveforms and Measurement Levels
AC
DRIVING
LEVELS
2.4V
1.5V
0.45V
AC
MEASUREMENT
LEVEL
tR, tF < 2 ns (10% to 90%)
12.8
Output Test Load
DEVICE
UNDER
TEST
30 pF
30
AT26F004
3588D–DFLASH–10/08
AT26F004
13. AC Waveforms
Figure 13-1. Serial Input Timing
tCSH
CS
tCSLH
tSCKL
tCSLS
tSCKH
tCSHH
tCSHS
SCK
tDS
SI
SO
tDH
MSB
LSB
MSB
HIGH-IMPEDANCE
Figure 13-2. Serial Output Timing
CS
tSCKH
tSCKL
tDIS
SCK
SI
tOH
tV
tV
SO
Figure 13-3. HOLD Timing – Serial Input
CS
SCK
tHHH
tHLS
tHLH
tHHS
HOLD
SI
SO
HIGH-IMPEDANCE
31
3588D–DFLASH–10/08
Figure 13-4. HOLD Timing – Serial Output
CS
SCK
tHHH
tHLS
tHLH
tHHS
HOLD
SI
tHLQZ
tHHQX
SO
Figure 13-5. WP Timing for Write Status Register Command When SPRL = 1
CS
tWPH
tWPS
WP
SCK
SI
0
MSB OF
WRITE STATUS REGISTER
OPCODE
SO
32
0
0
X
MSB
LSB OF
WRITE STATUS REGISTER
DATA BYTE
MSB OF
NEXT OPCODE
HIGH-IMPEDANCE
AT26F004
3588D–DFLASH–10/08
AT26F004
14. Ordering Information
14.1
Green Package Options (Pb/Halide-free/RoHS Compliant)
fSCK (MHz)
33
Note:
Ordering Code
Package
AT26F004-SSU
8S1
AT26F004-SU
8S2
AT26F004-MU(1)
8M1-A
Operation Range
Industrial
(-40° C to 85° C)
1. Contact Atmel for availability.
Package Type
8S1
8-lead, 0.150” Wide, Plastic Gull Wing Small Outline Package (JEDEC SOIC)
8S2
8-lead, 0.208” Wide, Plastic Gull Wing Small Outline Package (EIAJ SOIC)
8M1-A
8-pad, 6 x 5 x 1.00 mm Very Thin Micro Lead-frame Package (MLF)
33
3588D–DFLASH–10/08
15. Packaging Information
15.1
8S1 – JEDEC SOIC
C
1
E
E1
L
N
Ø
TOP VIEW
END VIEW
e
b
COMMON DIMENSIONS
(Unit of Measure = mm)
A
A1
SYMBOL
MIN
NOM
MAX
A1
0.10
–
0.25
NOTE
D
SIDE VIEW
Note: These drawings are for general information only. Refer to JEDEC Drawing MS-012, Variation AA for proper dimensions, tolerances, datums, etc.
3/17/05
R
34
1150 E. Cheyenne Mtn. Blvd.
Colorado Springs, CO 80906
TITLE
8S1, 8-lead (0.150" Wide Body), Plastic Gull Wing
Small Outline (JEDEC SOIC)
DRAWING NO.
REV.
8S1
C
AT26F004
3588D–DFLASH–10/08
AT26F004
15.2
8S2 – EIAJ SOIC
C
1
E
E1
L
N
θ
TOP VIEW
END VIEW
e
b
COMMON DIMENSIONS
(Unit of Measure = mm)
A
SYMBOL
A1
D
SIDE VIEW
MAX
NOM
NOTE
A
1.70
A1
0.05
0.25
b
0.35
0.48
4
C
0.15
0.35
4
D
5.13
5.35
E1
5.18
5.40
E
7.70
8.26
L
0.51
0.85
θ
0°
e
Notes: 1.
2.
3.
4.
MIN
2.16
2
8°
1.27 BSC
3
This drawing is for general information only; refer to EIAJ Drawing EDR-7320 for additional information.
Mismatch of the upper and lower dies and resin burrs aren't included.
Determines the true geometric position.
Values b,C apply to plated terminal. The standard thickness of the plating layer shall measure between 0.007 to .021 mm.
Package Drawing Contact:
[email protected]
TITLE
8S2, 8-lead, 0.208” Body, Plastic Small
Outline Package (EIAJ)
GPC
STN
4/15/08
DRAWING NO. REV.
8S2
F
35
3588D–DFLASH–10/08
15.3
8M1-A – MLF
D
D1
0
Pin 1 ID
E
E1
SIDE VIEW
TOP VIEW
A3
A2
A1
A
0.08 C
Pin #1 Notch
(0.20 R)
e
COMMON DIMENSIONS
(Unit of Measure = mm)
0.45
D2
E2
b
L
K
BOTTOM VIEW
SYMBOL
MIN
NOM
MAX
A
–
0.85
1.00
A1
–
–
0.05
A2
0.65 TYP
A3
0.20 TYP
b
0.35
0.40
0.48
D
5.90
6.00
6.10
D1
5.70
5.75
5.80
D2
3.20
3.40
3.60
E
4.90
5.00
5.10
E1
4.70
4.75
4.80
E2
3.80
4.00
4.20
e
NOTE
1.27
L
0.50
0.60
0.75
0
–
–
12o
K
0.25
–
–
8/28/08
Package Drawing Contact:
[email protected]
36
TITLE
8M1-A, 8-pad, 6 x 5 x 1.00 mm Body, Thermally
Enhanced Plastic Very Thin Dual Flat No
Lead Package (VDFN)
GPC
YBR
DRAWING NO.
8M1-A
REV.
D
AT26F004
3588D–DFLASH–10/08
AT26F004
16. Revision History
Revision Level – Release Date
History
A – October 2005
Initial release.
B – January 2006
Changed tCSLH parameter for SPI Mode 3 timing
C – April 2006
Changed Note 5 of 8S2 package drawing to generalize terminal
plating comment.
D – October 2008
No longer recommended for new designs. For new designs use
AT25DF041A.
37
3588D–DFLASH–10/08
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International
Atmel Corporation
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Sales Contact
www.atmel.com/contacts
Product Contact
Web Site
www.atmel.com
Literature Requests
www.atmel.com/literature
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3588D–DFLASH–10/08