– Allows Receiving of Data while Reprogramming the Flash Array
– Ideal for Code Shadowing Applications
– 7mA Active Read Current Typical
– 25µA Standby Current Typical
– 15µA Deep Power Down Typical
– Individual Sector
– Individual Sector
– 64-byte User Programmable Space
– Unique 64-byte Device Identifier
16-megabit
2.5V or 2.7V
DataFlash
AT45DB161D
1.Description
The AT45DB161D is a 2.5V or 2.7V, serial-interface sequential access Flash memory
ideally suited for a wide variety of digital voice-, image-, program code- and data-storage applications. The AT45DB161D supports RapidS serial interface for applications
requiring very high speed operations. RapidS serial interface is SPI compatible for
frequencies up to 66MHz. Its 17,301,504-bits of memory are organized as 4,096
pages of 512-bytes or 528-bytes each. In addition to the main memory, the
AT45DB161D also contains two SRAM buffers of 512-/528-bytes each. The buffers
allow the receiving of data while a page in the main Memory is being reprogrammed,
as well as writing a continuous data stream. EEPROM emulation (bit or byte alterability) is easily handled with a self-contained three step read-modify-write
3500O–DFLASH–11/2012
operation. Unlike conventional Flash memories that are accessed randomly with multiple address lines and a
®
parallel interface, the Adesto DataFlash
uses a RapidS serial interface to sequentially access its data. The simple
sequential access dramatically reduces active pin count, facilitates hardware layout, increases system reliability,
minimizes switching noise, and reduces package size. The device is optimized for use in many commercial and
industrial applications where high-density, low-pin count, low-voltage and low-power are essential.
To allow for simple in-system reprogrammability, the AT45DB161D does not require high input voltages for
programming. The device operates from a single power supply, 2.5V to 3.6V or 2.7V to 3.6V, for both the program
and read operations. The AT45DB161D is enabled through the chip select pin (CS) and accessed via a three-wire
interface consisting of the Serial Input (SI), Serial Output (SO), and the Serial Clock (SCK).
All programming and erase cycles are self-timed.
2.Pin Configurations and Pinouts
Figure 2-1.TSOP Top View: Type 1Figure 2-2.BGA Package Ball-out
(Top View)
RDY/BUSY
RESET
WP
NC
NC
VCC
GND
NC
NC
NC
CS
SCK
SO
1
2
3
4
5
6
7
8
9
10
11
12
13
SI
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
A
B
C
D
E
NCNCNCNC
NC
NC
CS RDY/BSY WP
NC
NCNC
NCNCNC
SISORESET
54321
NCVCCGNDSCK
NC
NC
Figure 2-3.MLF (VDFN) Top ViewFigure 2-4.SOIC Top View
1
SI
2
SCK
CS
3
4
RESET
Note:1. The metal pad on the bottom of the MLF package is floating. This pad can be a “No Connect” or connected to GND
2
AT45DB161D
8
7
6
5
SO
GND
VCC
WP
SI
SCK
RESET
CS
1
2
3
4
SO
8
GND
7
VCC
6
WP
5
3500O–DFLASH–11/2012
Table 2-1.Pin Configurations
SymbolName and Function
Chip Select: Asserting the
device will be deselected and normally be placed in the standby mode (not Deep Power-Down
mode), and the output pin (SO) will be in a high-impedance state. When the device is
CS
SCK
SI
deselected, data will not be accepted on the input pin (SI).
A high-to-low transition on the
transition is required to end an operation. When ending an internally self-timed operation such
as a program or erase cycle, the device will not enter the standby mode until the completion of
the operation.
Serial Clock: This pin is used to provide a clock to the device and is used to control the flow of
data to and from the device. Command, address, and input data present on the SI pin is always
latched on the rising edge of SCK, while output data on the SO pin is always clocked out on the
falling edge of SCK.
Serial Input: The SI pin is used to shift data into the device. The SI pin is used for all data input
including command and address sequences. Data on the SI pin is always latched on the rising
edge of SCK.
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
AT45DB161D
Asserte
d StateType
LowInput
–Input
–Input
SO
WP
RESET
RDY/
BUSY
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: When the
Protection Register will be protected against program and erase operations regardless of
whether the Enable Sector Protection command has been issued or not. The
independently of the software controlled protection method. After the
content of the Sector Protection Register cannot be modified.
If a program or erase command is issued to the device while the
will simply ignore the command and perform no operation. The device will return to the idle state
once the
Lockdown command, however, will be recognized by the device when the
The
not be used. However, it is recommended that the
whenever possible.
Reset: A low state on the reset pin (
the internal state machine to an idle state. The device will remain in the reset condition as long
as a low level is present on the
is brought back to a high level.
The device incorporates an internal power-on reset circuit, so there are no restrictions on the
RESET pin during power-on sequences. If this pin and feature are not utilized it is recommended
that the
Ready/Busy: This open drain output pin will be driven low when the device is busy in an
internally self-timed operation. This pin, which is normally in a high state (through an external
pull-up resistor), will be pulled low during programming/erase operations, compare operations,
and page-to-buffer transfers.
The busy status indicates that the Flash memory array and one of the buffers cannot be
accessed; read and write operations to the other buffer can still be performed.
CS pin has been deasserted. The Enable Sector Protection command and Sector
WP pin is internally pulled-high and may be left floating if hardware controlled protection will
RESET pin be driven high externally.
WP pin is asserted, all sectors specified for protection by the Sector
WP pin functions
WP pin goes low, the
WP pin is asserted, the device
WP pin is asserted.
WP pin also be externally connected to V
RESET) will terminate the operation in progress and reset
RESET pin. Normal operation can resume once the RESET pin
CC
–
LowInput
LowInput
–
Outpu
t
Outpu
t
V
CC
GND
3500O–DFLASH–11/2012
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.
voltages may produce spurious results and should not be attempted.
CC
–Power
–
Groun
d
3
3.Block Diagram
WP
SCK
CS
RESET
VCC
GND
RDY/BUSY
4.Memory Array
To provide optimal flexibility, the memory array of the AT45DB161D is divided into three levels of granularity
comprising of sectors, blocks, and pages. The “Memory Architecture Diagram” illustrates the breakdown of each
level and details the number of pages per sector and block. All program operations to the DataFlash occur on a
page by page basis. The erase operations can be performed at the chip, sector, block or page level.
The device operation is controlled by instructions from the host processor. The list of instructions and their
associated opcodes are contained in Table 15-1 on page 27 through Table 15-7 on page 30. A valid instruction
starts with the falling edge of
address location. While the
buffer or main memory address location through the SI (serial input) pin. All instructions, addresses, and data are
transferred with the most significant bit (MSB) first.
Buffer addressing for standard DataFlash page size (528-bytes) is referenced in the datasheet using the
terminology BFA9 - BFA0 to denote the 10 address bits required to designate a byte address within a buffer. Main
memory addressing is referenced using the terminology PA11 - PA0 and BA9 - BA0, where PA11 - PA0 denotes
the 12 address bits required to designate a page address and BA9 - BA0 denotes the 10 address bits required to
designate a byte address within the page.
For “Power of 2” binary page size (512-bytes) the Buffer addressing is referenced in the datasheet using the
conventional terminology BFA8 - BFA0 to denote the nine address bits required to designate a byte address within
a buffer. Main memory addressing is referenced using the terminology A20 - A0, where A20 - A9 denotes the 12
address bits required to designate a page address and A8 - A0 denotes the nine address bits required to designate
a byte address within a page.
AT45DB161D
CS followed by the appropriate 8-bit opcode and the desired buffer or main memory
CS pin is low, toggling the SCK pin controls the loading of the opcode and the desired
6.Read Commands
By specifying the appropriate opcode, data can be read from the main memory or from either one of the two SRAM
data buffers. The DataFlash supports RapidS protocols for Mode 0 and Mode 3. Please refer to the “Detailed Bitlevel Read Timing” diagrams in this datasheet for details on the clock cycle sequences for each mode.
6.1Continuous Array Read (Legacy Command: E8H): Up to 66MHz
By supplying an initial starting address for the main memory array, the Continuous Array Read command can be
utilized to sequentially read a continuous stream of data from the device by simply providing a clock signal; no
additional addressing information or control signals need to be provided. The DataFlash incorporates an internal
address counter that will automatically increment on every clock cycle, allowing one continuous read operation
without the need of additional address sequences. To perform a continuous read from the standard DataFlash
page size (528-bytes), an opcode of E8H must be clocked into the device followed by three address bytes (which
comprise the 24-bit page and byte address sequence) and four don’t care bytes. The first 12 bits (PA11 - PA0) of
the 22-bit address sequence specify which page of the main memory array to read, and the last 10 bits (BA9 -
BA0) of the 22-bit address sequence specify the starting byte address within the page. To perform a continuous
read from the binary page size (512-bytes), the opcode (E8H) must be clocked into the device followed by three
address bytes and four don’t care bytes. The first 12 bits (A20 - A9) of the 21-bits sequence specify which page of
the main memory array to read, and the last nine bits (A8 - A0) of the 21-bits address sequence specify the starting
byte address within the page. The don’t care bytes that follow the address bytes are needed to initialize the read
operation. Following the don’t care bytes, additional clock pulses on the SCK pin will result in data being output on
the SO (serial output) pin.
The CS pin must remain low during the loading of the opcode, the address bytes, the don’t care bytes, and the
reading of data. When the end of a page in main memory is reached during a Continuous Array Read, the device
will continue reading at the beginning of the next page with no delays incurred during the page boundary crossover
(the crossover from the end of one page to the beginning of the next page). When the last bit in the main memory
array has been read, the device will continue reading back at the beginning of the first page of memory. As with
crossing over page boundaries, no delays will be incurred when wrapping around from the end of the array to the
beginning of the array.
3500O–DFLASH–11/2012
5
A low-to-high transition on the CS pin will terminate the read operation and tri-state the output pin (SO). The
maximum SCK frequency allowable for the Continuous Array Read is defined by the f
Continuous Array Read bypasses both data buffers and leaves the contents of the buffers unchanged.
6.2Continuous Array Read (High Frequency Mode: 0BH): Up to 66MHz
This command can be used with the serial interface to read the main memory array sequentially in high speed
mode for any clock frequency up to the maximum specified by f
page size set to 528-bytes, the
CS must first be asserted then an opcode 0BH must be clocked into the device
followed by three address bytes and a dummy byte. The first 12 bits (PA11 - PA0) of the 22-bit address sequence
specify which page of the main memory array to read, and the last 10 bits (BA9 - BA0) of the 22-bit address
sequence specify the starting byte address within the page. To perform a continuous read with the page size set to
512-bytes, the opcode, 0BH, must be clocked into the device followed by three address bytes (A20 - A0) and a
dummy byte. Following the dummy byte, additional clock pulses on the SCK pin will result in data being output on
the SO (serial output) pin.
The CS pin must remain low during the loading of the opcode, the address bytes, and the reading of data. When
the end of a page in the main memory is reached during a Continuous Array Read, the device will continue reading
at the beginning of the next page with no delays incurred during the page boundary crossover (the crossover from
the end of one page to the beginning of the next page). When the last bit in the main memory array has been read,
the device will continue reading back at the beginning of the first page of memory. As with crossing over page
boundaries, no delays will be incurred when wrapping around from the end of the array to the beginning of the
array. A low-to-high transition on the CS pin will terminate the read operation and tri-state the output pin (SO). The
maximum SCK frequency allowable for the Continuous Array Read is defined by the f
Continuous Array Read bypasses both data buffers and leaves the contents of the buffers unchanged.
. To perform a continuous read array with the
CAR1
specification. The
CAR1
specification. The
CAR1
6.3Continuous Array Read (Low Frequency Mode: 03H): Up to 33MHz
This command can be used with the serial interface to read the main memory array sequentially without a dummy
byte up to maximum frequencies specified by f
528-bytes, the CS must first be asserted then an opcode, 03H, must be clocked into the device followed by three
address bytes (which comprise the 24-bit page and byte address sequence). The first 12 bits (PA11 - PA0) of the
22-bit address sequence specify which page of the main memory array to read, and the last 10 bits (BA9 - BA0) of
the 22-bit address sequence specify the starting byte address within the page. To perform a continuous read with
the page size set to 512-bytes, the opcode, 03H, must be clocked into the device followed by three address bytes
(A20 - A0). Following the address bytes, additional clock pulses on the SCK pin will result in data being output on
the SO (serial output) pin.
The CS pin must remain low during the loading of the opcode, the address bytes, and the reading of data. When
the end of a page in the main memory is reached during a Continuous Array Read, the device will continue reading
at the beginning of the next page with no delays incurred during the page boundary crossover (the crossover from
the end of one page to the beginning of the next page). When the last bit in the main memory array has been read,
the device will continue reading back at the beginning of the first page of memory. As with crossing over page
boundaries, no delays will be incurred when wrapping around from the end of the array to the beginning of the
array. A low-to-high transition on the CS pin will terminate the read operation and tri-state the output pin (SO). The
Continuous Array Read bypasses both data buffers and leaves the contents of the buffers unchanged.
. To perform a continuous read array with the page size set to
CAR2
6
AT45DB161D
3500O–DFLASH–11/2012
6.4Main Memory Page Read
A main memory page read allows the user to read data directly from any one of the 4,096 pages in the main
memory, bypassing both of the data buffers and leaving the contents of the buffers unchanged. To start a page
read from the standard DataFlash page size (528-bytes), an opcode of D2H must be clocked into the device
followed by three address bytes (which comprise the 24-bit page and byte address sequence) and four don’t care
bytes. The first 12 bits (PA11 - PA0) of the 22-bit address sequence specify the page in main memory to be read,
and the last 10 bits (BA9 - BA0) of the 22-bit address sequence specify the starting byte address within that page.
To start a page read from the binary page size (512-bytes), the opcode D2H must be clocked into the device
followed by three address bytes and four don’t care bytes. The first 12 bits (A20 - A9) of the 21-bits sequence
specify which page of the main memory array to read, and the last nine bits (A8 - A0) of the 21-bits address
sequence specify the starting byte address within the page. The don’t care bytes that follow the address bytes are
sent to initialize the read operation. Following the don’t care bytes, additional pulses on SCK result in data being
output on the SO (serial output) pin. The
bytes, the don’t care bytes, and the reading of data. When the end of a page in main memory is reached, the
device will continue reading back at the beginning of the same page. A low-to-high transition on the CS pin will
terminate the read operation and tri-state the output pin (SO). The maximum SCK frequency allowable for the Main
Memory Page Read is defined by the f
and leaves the contents of the buffers unchanged.
AT45DB161D
CS pin must remain low during the loading of the opcode, the address
specification. The Main Memory Page Read bypasses both data buffers
SCK
6.5Buffer Read
The SRAM data buffers can be accessed independently from the main memory array, and utilizing the Buffer Read
Command allows data to be sequentially read directly from the buffers. Four opcodes, D4H or D1H for buffer 1 and
D6H or D3H for buffer 2 can be used for the Buffer Read Command. The use of each opcode depends on the
maximum SCK frequency that will be used to read data from the buffer. The D4H and D6H opcode can be used at
any SCK frequency up to the maximum specified by f
frequency read operations up to the maximum specified by f
To perform a buffer read from the standard DataFlash buffer (528-bytes), the opcode must be clocked into the
device followed by three address bytes comprised of 14 don’t care bits and 10 buffer address bits (BFA9 - BFA0).
To perform a buffer read from the binary buffer (512-bytes), the opcode must be clocked into the device followed
by three address bytes comprised of 15 don’t care bits and nine buffer address bits (BFA8 - BFA0). Following the
address bytes, one don’t care byte must be clocked in to initialize the read operation. The CS pin must remain low
during the loading of the opcode, the address bytes, the don’t care bytes, and the reading of data. When the end of
a buffer is reached, the device will continue reading back at the beginning of the buffer. A low-to-high transition on
the CS pin will terminate the read operation and tri-state the output pin (SO).
. The D1H and D3H opcode can be used for lower
CAR1
.
CAR2
3500O–DFLASH–11/2012
7
7.Program and Erase Commands
7.1Buffer Write
Data can be clocked in from the input pin (SI) into either buffer 1 or buffer 2. To load data into the standard
DataFlash buffer (528-bytes), a 1-byte opcode, 84H for buffer 1 or 87H for buffer 2, must be clocked into the
device, followed by three address bytes comprised of 14 don’t care bits and 10 buffer address bits (BFA9 - BFA0).
The 10 buffer address bits specify the first byte in the buffer to be written. To load data into the binary buffers (512bytes each), a 1-byte opcode 84H for buffer 1 or 87H for buffer 2, must be clocked into the device, followed by
three address bytes comprised of 15 don’t care bits and nine buffer address bits (BFA8 - BFA0). The nine buffer
address bits specify the first byte in the buffer to be written. After the last address byte has been clocked into the
device, data can then be clocked in on subsequent clock cycles. If the end of the data buffer is reached, the device
will wrap around back to the beginning of the buffer. Data will continue to be loaded into the buffer until a low-tohigh transition is detected on the
7.2Buffer to Main Memory Page Program with Built-in Erase
Data written into either buffer 1 or buffer 2 can be programmed into the main memory. A 1-byte opcode, 83H for
buffer 1 or 86H for buffer 2, must be clocked into the device. For the standard DataFlash page size (528-bytes), the
opcode must be followed by three address bytes consist of two don’t care bits, 12 page address bits (PA11 - PA0)
that specify the page in the main memory to be written and 10 don’t care bits. To perform a buffer to main memory
page program with built-in erase for the binary page size (512-bytes), the opcode 83H for buffer 1 or 86H for buffer
2, must be clocked into the device followed by three address bytes consisting of three don’t care bits 12 page
address bits (A20 - A9) that specify the page in the main memory to be written and nine don’t care bits. When a
low-to-high transition occurs on the CS pin, the part will first erase the selected page in main memory (the erased
state is a logic 1) and then program the data stored in the buffer into the specified page in main memory. Both the
erase and the programming of the page are internally self-timed and should take place in a maximum time of tEP.
During this time, the status register and the RDY/BUSY pin will indicate that the part is busy.
CS pin.
7.3Buffer to Main Memory Page Program without Built-in Erase
A previously-erased page within main memory can be programmed with the contents of either buffer 1 or buffer 2.
A 1-byte opcode, 88H for buffer 1 or 89H for buffer 2, must be clocked into the device. For the standard DataFlash
page size (528-bytes), the opcode must be followed by three address bytes consist of two don’t care bits, 12 page
address bits (PA11 - PA0) that specify the page in the main memory to be written and 10 don’t care bits. To
perform a buffer to main memory page program without built-in erase for the binary page size (512-bytes), the
opcode 88H for buffer 1 or 89H for buffer 2, must be clocked into the device followed by three address bytes
consisting of three don’t care bits, 12 page address bits (A20 - A9) that specify the page in the main memory to be
written and nine don’t care bits. When a low-to-high transition occurs on the CS pin, the part will program the data
stored in the buffer into the specified page in the main memory. It is necessary that the page in main memory that
is being programmed has been previously erased using one of the erase commands (Page Erase or Block Erase).
The programming of the page is internally self-timed and should take place in a maximum time of tP. During this
time, the status register and the RDY/BUSY pin will indicate that the part is busy.
7.4Page Erase
The Page Erase command can be used to individually erase any page in the main memory array allowing the
Buffer to Main Memory Page Program to be utilized at a later time. To perform a page erase in the standard
DataFlash page size (528-bytes), an opcode of 81H must be loaded into the device, followed by three address
bytes comprised of two don’t care bits, 12 page address bits (PA11 - PA0) that specify the page in the main
memory to be erased and 10 don’t care bits. To perform a page erase in the binary page size (512-bytes), the
opcode 81H must be loaded into the device, followed by three address bytes consist of three don’t care bits, 12
8
AT45DB161D
3500O–DFLASH–11/2012
page address bits (A20 - A9) that specify the page in the main memory to be erased and nine don’t care bits. When
a low-to-high transition occurs on the
The erase operation is internally self-timed and should take place in a maximum time of tPE. During this time, the
status register and the RDY/
7.5Block Erase
A block of eight pages can be erased at one time. This command is useful when large amounts of data has to be
written into the device. This will avoid using multiple Page Erase Commands. To perform a block erase for the
standard DataFlash page size (528-bytes), an opcode of 50H must be loaded into the device, followed by three
address bytes comprised of two don’t care bits, nine page address bits (PA11 -PA3) and 13 don’t care bits. The
nine page address bits are used to specify which block of eight pages is to be erased. To perform a block erase for
the binary page size (512-bytes), the opcode 50H must be loaded into the device, followed by three address bytes
consisting of three don’t care bits, nine page address bits (A20 - A12) and 12 don’t care bits. The nine page
address bits are used to specify which block of eight pages is to be erased. When a low-to-high transition occurs
on the
should take place in a maximum time of t
indicate that the part is busy.
Table 7-1.Block Erase Addressing
CS pin, the part will erase the selected block of eight pages. The erase operation is internally self-timed and
CS pin, the part will erase the selected page (the erased state is a logical 1).
BUSY pin will indicate that the part is busy.
. During this time, the status register and the RDY/BUSY pin will
BE
AT45DB161D
PA11/
A20
PA10/
A19
000000000XXX 0
000000001XXX 1
000000010XXX 2
000000011XXX 3
•
•
•
111111100XXX 508
111111101XXX 509
111111110XXX 510
111111111XXX 511
•
•
•
7.6Sector Erase
The Sector Erase command can be used to individually erase any sector in the main memory. There are 16
sectors and only one sector can be erased at one time. To perform sector 0a or sector 0b erase for the standard
DataFlash page size (528-bytes), an opcode of 7CH must be loaded into the device, followed by three address
bytes comprised of two don’t care bits, nine page address bits (PA11 - PA3) and 13 don’t care bits. To perform a
sector 1-15 erase, the opcode 7CH must be loaded into the device, followed by three address bytes comprised of
two don’t care bits, four page address bits (PA11 - PA8) and 18 don’t care bits. To perform sector 0a or sector 0b
erase for the binary page size (512-bytes), an opcode of 7CH must be loaded into the device, followed by three
address bytes comprised of three don’t care bit and nine page address bits (A20 - A12) and 12 don’t care bits. To
perform a sector 1-15 erase, the opcode 7CH must be loaded into the device, followed by three address bytes
comprised of 3 don’t care bit and four page address bits (A20 - A17) and 17 don’t care bits. The page address bits
are used to specify any valid address location within the sector which is to be erased. When a low-to-high transition
occurs on the CS pin, the part will erase the selected sector. The erase operation is internally self-timed and should
PA9/
A18
•
•
•
PA8/
A17
•
•
•
PA7/
A16
•
•
•
PA6/
A15
•
•
•
PA5/
A14
•
•
•
PA4/
A13
•
•
•
PA3/
A12
•
•
•
PA2/
A11
•
•
•
PA1/
A10
•
•
•
PA0/
A9Block
•
•
•
•
•
•
3500O–DFLASH–11/2012
9
take place in a maximum time of tSE. During this time, the status register and the RDY/BUSY pin will indicate that
the part is busy.
Table 7-2.Sector Erase Addressing
PA11/
A20
PA10/
A19
000000000XXX 0a
000000001XXX 0b
00 01XXXXXXXX1
00 10XXXXXXXX2
•
•
•
11 00XXXXXXXX 12
11 01XXXXXXXX 13
11 10XXXXXXXX 14
11 11XXXXXXXX 15
•
•
•
7.7Chip Erase
The entire main memory can be erased at one time by using the Chip Erase command.
To execute the Chip Erase command, a 4-byte command sequence C7H, 94H, 80H and 9AH 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. After the last bit of the opcode sequence has been
clocked in, the CS pin can be deasserted to start the erase process. The erase operation is internally self-timed
and should take place in a time of tCE. During this time, the Status Register will indicate that the device is busy.
(1)
PA9/
A18
•
•
•
PA8/
A17
•
•
•
PA7/
A16
•
•
•
PA6/
A15
•
•
•
PA5/
A14
•
•
•
PA4/
A13
•
•
•
PA3/
A12
•
•
•
PA2/
A11
•
•
•
PA1/
A10
•
•
•
PA0/
A9Sector
•
•
•
•
•
•
The Chip Erase command will not affect sectors that are protected or locked down; the contents of those sectors
will remain unchanged. Only those sectors that are not protected or locked down will be erased.
Note:1. Refer to the errata regarding Chip Erase on page 50.
The WP pin can be asserted while the device is erasing, but protection will not be activated until the internal erase
cycle completes.
Table 7-3.Chip Erase Command
CommandByte 1Byte 2Byte 3Byte 4
Chip EraseC7H94H80H9AH
Figure 7-1.Chip Erase
CS
SI
Each transition
represents eight bits
Note:1. Refer to the errata regarding Chip Erase on page 50
Opcode
Byte 1
Opcode
Byte 2
Opcode
Byte 3
Opcode
Byte 4
10
AT45DB161D
3500O–DFLASH–11/2012
7.8Main Memory Page Program Through Buffer
This operation is a combination of the Buffer Write and Buffer to Main Memory Page Program with Built-in Erase
operations. Data is first clocked into buffer 1 or buffer 2 from the input pin (SI) and then programmed into a
specified page in the main memory. To perform a main memory page program through buffer for the standard
DataFlash page size (528-bytes), a 1-byte opcode, 82H for buffer 1 or 85H for buffer 2, must first be clocked into
the device, followed by three address bytes. The address bytes are comprised of two don’t care bits, 12 page
address bits, (PA11 - PA0) that select the page in the main memory where data is to be written, and 10 buffer
address bits (BFA9 - BFA0) that select the first byte in the buffer to be written. To perform a main memory page
program through buffer for the binary page size (512-bytes), the opcode 82H for buffer 1 or 85H for buffer 2, must
be clocked into the device followed by three address bytes consisting of three don’t care bits, 12 page address bits
(A20 - A9) that specify the page in the main memory to be written, and 9 buffer address bits (BFA8 - BFA0) that
selects the first byte in the buffer to be written. After all address bytes are clocked in, the part will take data from the
input pins and store it in the specified data buffer. If the end of the buffer is reached, the device will wrap around
back to the beginning of the buffer. When there is a low-to-high transition on the CS pin, the part will first erase the
selected page in main memory to all 1s and then program the data stored in the buffer into that memory page. Both
the erase and the programming of the page are internally self-timed and should take place in a maximum time of
t
. During this time, the status register and the RDY/BUSY pin will indicate that the part is busy.
EP
8.Sector Protection
Two protection methods, hardware and software controlled, are provided for protection against inadvertent or
erroneous program and erase cycles. The software controlled method relies on the use of software commands to
enable and disable sector protection while the hardware controlled method employs the use of the Write Protect
(WP) pin. The selection of which sectors that are to be protected or unprotected against program and erase
operations is specified in the nonvolatile Sector Protection Register. The status of whether or not sector protection
has been enabled or disabled by either the software or the hardware controlled methods can be determined by
checking the Status Register.
AT45DB161D
8.1Software Sector Protection
8.1.1Enable Sector Protection Command
Sectors specified for protection in the Sector Protection Register can be protected from program and erase
operations by issuing the Enable Sector Protection command. To enable the sector protection using the software
controlled method, the CS pin must first be asserted as it would be with any other command. Once the CS pin has
been asserted, the appropriate 4-byte command sequence must be clocked in via the input pin (SI). After the last
bit of the command sequence has been clocked in, the CS pin must be deasserted after which the sector
protection will be enabled.
Table 8-1.Enable Sector Protection Command
CommandByte 1Byte 2Byte 3Byte 4
Enable Sector Protection3DH2AH7FHA9H
Figure 8-1.Enable Sector Protection
CS
SI
Opcode
Byte 1
Each transition
represents eight bits
Opcode
Byte 2
Opcode
Byte 3
Opcode
Byte 4
3500O–DFLASH–11/2012
11
8.1.2Disable Sector Protection Command
To disable the sector protection using the software controlled method, the
be with any other command. Once the
Sector Protection command must be clocked in via the input pin (SI). After the last bit of the command sequence
has been clocked in, the
CS pin must be deasserted after which the sector protection will be disabled. The WP pin
must be in the deasserted state; otherwise, the Disable Sector Protection command will be ignored.
Table 8-2.Disenable Sector Protection Command
CommandByte 1Byte 2Byte 3Byte 4
Disable Sector Protection3DH2AH7FH9AH
Figure 8-2.Disable Sector Protection
CS
CS pin must first be asserted as it would
CS pin has been asserted, the appropriate 4-byte sequence for the Disable
SI
Opcode
Byte 1
Each transition
represents eight bits
Opcode
Byte 2
Opcode
Byte 3
Opcode
Byte 4
8.1.3Various Aspects About Software Controlled Protection
Software controlled protection is useful in applications in which the
processor. In such instances, the WP pin may be left floating (the WP pin is internally pulled high) and sector
protection can be controlled using the Enable Sector Protection and Disable Sector Protection commands.
If the device is power cycled, then the software controlled protection will be disabled. Once the device is powered
up, the Enable Sector Protection command should be reissued if sector protection is desired and if the WP pin is
not used.
9.Hardware Controlled Protection
Sectors specified for protection in the Sector Protection Register and the Sector Protection Register itself can be
protected from program and erase operations by asserting the WP pin and keeping the pin in its asserted state.
The Sector Protection Register and any sector specified for protection cannot be erased or reprogrammed as long
as the WP pin is asserted. In order to modify the Sector Protection Register, the WP pin must be deasserted. If the
WP pin is permanently connected to GND, then the content of the Sector Protection Register cannot be changed.
If the WP pin is deasserted, or permanently connected to VCC, then the content of the Sector Protection Register
can be modified.
WP pin is not or cannot be controlled by a host
12
The WP pin will override the software controlled protection method but only for protecting the sectors. For example,
if the sectors were not previously protected by the Enable Sector Protection command, then simply asserting the
WP pin would enable the sector protection within the maximum specified t
deasserted; however, the sector protection would no longer be enabled (after the maximum specified t
time. When the WP pin is
WPE
WPD
time) as
long as the Enable Sector Protection command was not issued while the WP pin was asserted. If the Enable
Sector Protection command was issued before or while the WP pin was asserted, then simply deasserting the WP
pin would not disable the sector protection. In this case, the Disable Sector Protection command would need to be
issued while the WP pin is deasserted to disable the sector protection. The Disable Sector Protection command is
also ignored whenever the WP pin is asserted.
A noise filter is incorporated to help protect against spurious noise that may inadvertently assert or deassert the
WP pin.
AT45DB161D
3500O–DFLASH–11/2012
AT45DB161D
The table below details the sector protection status for various scenarios of the WP pin, the Enable Sector
Protection command, and the Disable Sector Protection command.
Figure 9-1.
WP Pin and Protection Status
12
WP
Table 9-1.
Time
Period
1High
2LowXXEnabledRead Only
3High
WP Pin and Protection Status
WP PinEnable Sector Protection Command
Command Not Issued Previously
Issue Command
Command Issued During Period 1 or 2
Issue Command
9.1Sector Protection Register
The nonvolatile Sector Protection Register specifies which sectors are to be protected or unprotected with either
the software or hardware controlled protection methods. The Sector Protection Register contains 16-bytes of data,
of which byte locations 0 through 15 contain values that specify whether sectors 0 through 15 will be protected or
unprotected. The Sector Protection Register is user modifiable and must first be erased before it can be
reprogrammed. Table 9-3 illustrates the format of the Sector Protection Register.:
3
Sector
Disable Sector
Protection Command
X
–
–
Issue Command
–
Not Issued Yet
Issue Command
–
Protection
Status
Disabled
Disabled
Enabled
Enabled
Disabled
Enabled
Sector
Protection
Register
Read/Write
Read/Write
Read/Write
Read/Write
Read/Write
Read/Write
Table 9-2.Sector Protection Register
Sector Number0 (0a, 0b)1 to 15
Protected
See Table 9-3
Unprotected00H
FFH
Table 9-3.Sector 0 (0a, 0b)
0a0b
(Page 0-7)(Page 8-255)
Bit7,6Bit5,4Bit1,0
Sectors 0a, 0b Unprotected0000xxxx0xH
Protect Sector 0a1100xxxxCxH
Protect Sector 0b (Page 8-255)0011xxxx3xH
Protect Sectors 0a (Page 0-7), 0b (Page 8-255)
Note:1. The default value for bytes 0 through 15 when shipped from Adesto is 00H
x = don’t care
(1)
1111xxxxFxH
Bit3,2
Value
Data
3500O–DFLASH–11/2012
13
9.1.1Erase Sector Protection Register Command
In order to modify and change the values of the Sector Protection Register, it must first be erased using the Erase
Sector Protection Register command.
To erase the Sector Protection Register, the
CS pin must first be asserted as it would be with any other command.
Once the CS pin has been asserted, the appropriate 4-byte opcode sequence must be clocked into the device via
the SI pin. The 4-byte opcode sequence must start with 3DH and be followed by 2AH, 7FH, and CFH. After the last
bit of the opcode sequence has been clocked in, the CS pin must be deasserted to initiate the internally self-timed
erase cycle. The erasing of the Sector Protection Register should take place in a time of t
, during which time the
PE
Status Register will indicate that the device is busy. If the device is powered-down before the completion of the
erase cycle, then the contents of the Sector Protection Register cannot be guaranteed.
The Sector Protection Register can be erased with the sector protection enabled or disabled. Since the erased
state (FFH) of each byte in the Sector Protection Register is used to indicate that a sector is specified for
protection, leaving the sector protection enabled during the erasing of the register allows the protection scheme to
be more effective in the prevention of accidental programming or erasing of the device. If for some reason an
erroneous program or erase command is sent to the device immediately after erasing the Sector Protection
Register and before the register can be reprogrammed, then the erroneous program or erase command will not be
processed because all sectors would be protected.
Once the Sector Protection Register has been erased, it can be reprogrammed using the Program Sector
Protection Register command.
To program the Sector Protection Register, the CS pin must first be asserted and the appropriate 4-byte opcode
sequence must be clocked into the device via the SI pin. The 4-byte opcode sequence must start with 3DH and be
followed by 2AH, 7FH, and FCH. After the last bit of the opcode sequence has been clocked into the device, the
data for the contents of the Sector Protection Register must be clocked in. As described in Section 9.1, the Sector
Protection Register contains 16-bytes of data, so 16-bytes must be clocked into the device. The first byte of data
corresponds to sector 0, the second byte corresponds to sector 1, and so on with the last byte of data
corresponding to sector 15.
After the last data byte has been clocked in, the CS pin must be deasserted to initiate the internally self-timed
program cycle. The programming of the Sector Protection Register should take place in a time of tP, during which
time the Status Register will indicate that the device is busy. If the device is powered-down during the program
cycle, then the contents of the Sector Protection Register cannot be guaranteed.
If the proper number of data bytes is not clocked in before the CS pin is deasserted, then the protection status of
the sectors corresponding to the bytes not clocked in can not be guaranteed. For example, if only the first two bytes
are clocked in instead of the complete 16-bytes, then the protection status of the last 14 sectors cannot be
Opcode
Byte 4
14
AT45DB161D
3500O–DFLASH–11/2012
AT45DB161D
guaranteed. Furthermore, if more than 16-bytes of data is clocked into the device, then the data will wrap back
th
around to the beginning of the register. For instance, if 17-bytes of data are clocked in, then the 17
byte will be
stored at byte location 0 of the Sector Protection Register.
If a value other than 00H or FFH is clocked into a byte location of the Sector Protection Register, then the
protection status of the sector corresponding to that byte location cannot be guaranteed. For example, if a value of
17H is clocked into byte location 2 of the Sector Protection Register, then the protection status of sector 2 cannot
be guaranteed.
The Sector Protection Register can be reprogrammed while the sector protection enabled or disabled. Being able
to reprogram the Sector Protection Register with the sector protection enabled allows the user to temporarily
disable the sector protection to an individual sector rather than disabling sector protection completely.
The Program Sector Protection Register command utilizes the internal SRAM buffer 1 for processing. Therefore,
the contents of the buffer 1 will be altered from its previous state when this command is issued.
CS pin must first be asserted. Once the CS pin has been asserted, an
opcode of 32H and three dummy bytes must be clocked in via the SI pin. After the last bit of the opcode and
dummy bytes have been clocked in, any additional clock pulses on the SCK pins will result in data for the content
of the Sector Protection Register being output on the SO pin. The first byte corresponds to sector 0 (0a, 0b), the
second byte corresponds to sector 1 and the last byte (byte 16) corresponds to sector 15. Once the last byte of the
Sector Protection Register has been clocked out, any additional clock pulses will result in undefined data being
output on the SO pin. The CS must be deasserted to terminate the Read Sector Protection Register operation and
put the output into a high-impedance state.
Table 9-6.Read Sector Protection Register Command
CommandByte 1Byte 2Byte 3Byte 4
Read Sector Protection Register32HxxHxxHxxH
Note:xx = Dummy Byte
Figure 9-4.Read Sector Protection Register
CS
SI
Opcode X X X
SO
3500O–DFLASH–11/2012
Each transition
represents eight bits
Data Byte n Data Byte
n + 1
Data Byte
n + 15
15
9.1.4Various Aspects About the Sector Protection Register
The Sector Protection Register is subject to a limit of 10,000 erase/program cycles. Users are encouraged to
carefully evaluate the number of times the Sector Protection Register will be modified during the course of the
applications’ life cycle. If the application requires that the Sector Protection Register be modified more than the
specified limit of 10,000 cycles because the application needs to temporarily unprotect individual sectors (sector
protection remains enabled while the Sector Protection Register is reprogrammed), then the application will need
to limit this practice. Instead, a combination of temporarily unprotecting individual sectors along with disabling
sector protection completely will need to be implemented by the application to ensure that the limit of 10,000 cycles
is not exceeded.
10.Security Features
10.1Sector Lockdown
The device incorporates a Sector Lockdown mechanism that allows each individual sector to be permanently
locked so that it becomes read only. This is useful for applications that require the ability to permanently protect a
number of sectors against malicious attempts at altering program code or security information. Onceasectoris
locked down, it can never be erased or programmed, and it can never be unlocked.
To issue the Sector Lockdown command, the CS pin must first be asserted as it would be for any other command.
Once the CS pin has been asserted, the appropriate 4-byte opcode sequence must be clocked into the device in
the correct order. The 4-byte opcode sequence must start with 3DH and be followed by 2AH, 7FH, and 30H. After
the last byte of the command sequence has been clocked in, then three address bytes specifying any address
within the sector to be locked down must be clocked into the device. After the last address bit has been clocked in,
the CS pin must then be deasserted to initiate the internally self-timed lockdown sequence.
The lockdown sequence should take place in a maximum time of tP, during which time the Status Register will
indicate that the device is busy. If the device is powered-down before the completion of the lockdown sequence,
then the lockdown status of the sector cannot be guaranteed. In this case, it is recommended that the user read the
Sector Lockdown Register to determine the status of the appropriate sector lockdown bits or bytes and reissue the
Sector Lockdown command if necessary.
Table 10-1.Sector Lockdown
CommandByte 1Byte 2Byte 3Byte 4
Sector Lockdown3DH2AH7FH30H
Figure 10-1. Sector Lockdown
CS
SI
Each transition
represents eight bits
Opcode
Byte 1
Opcode
Byte 2
Opcode
Byte 3
Opcode
Byte 4
Address
Bytes
Address
Bytes
Address
Bytes
16
AT45DB161D
3500O–DFLASH–11/2012
Loading...
+ 35 hidden pages
You need points to download manuals.
1 point = 1 manual.
You can buy points or you can get point for every manual you upload.