Rainbow Electronics AT26DF081A User Manual

Download

Features

• Single 2.7V - 3.6V Supply

• Serial Peripheral Interface (SPI) Compatible

– Supports SPI Modes 0 and 3

• 70 MHz Maximum Clock Frequency

• Flexible, Uniform Erase Architecture

– 4-Kbyte Blocks – 32-Kbyte Blocks – 64-Kbyte Blocks – Full Chip Erase

• Individual Sector Protection with Global Protect/Unprotect Feature

– One 32-Kbyte Top Boot Sector – Two 8-Kbyte Sectors – One 16-Kbyte Sector – Fifteen 64-Kbyte Sectors

• Hardware Controlled Locking of Protected Sectors

• Flexible Programming Options

– Byte/Page Program (1 to 256 Bytes) – Sequential Program Mode Capability

• Automatic Checking and Reporting of Erase/Program Failures

• JEDEC Standard Manufacturer and Device ID Read Methodology

• Low Power Dissipation

– 5 mA Active Read Current (Typical) – 25 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 200-mil wide)

8-megabit

2.7-volt Minimum SPI Serial Flash Memory

AT26DF081A

1. Description

The AT26DF081A 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 AT26DF081A, with its eras\e 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 AT26DF081A 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.

3600H–DFLASH–11/2012

The AT26DF081A also offers a sophisticated method for protecting individual sectors against erroneous or malicious program and erase operations. By providing the ability to individually protect and unprotect sectors, a system can unprotect a specific sector to modify its contents while keeping the remaining sectors of the memory array securely protected. This is useful in applications where program code is patched or updated on a subroutine or module basis, or in applications where data storage segments need to be modified without running the risk of errant modifications to the program code segments. In addition to individual sector protection capabilities, the AT26DF081A incorporates Global Protect and Global Unprotect features that allow the entire memory array to be either protected or unprotected all at once. This reduces overhead during the manufacturing process since sectors do not have to be unprotected one-by-one prior to initial programming.

Specifically designed for use in 3-volt systems, the AT26DF081A 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.

AT26DF081A

3600H–DFLASH–11/2012

2. Pin Descriptions and Pinouts

Table 2-1. Pin Descriptions

Symbol Name and Function

SCK

CHIP SELECT: Asserting the device will be deselected and normally be placed in standby mode (not Deep Power-down mode), and the SO pin will be in a high-impedance state. When the device is deselected, data will not be accepted on the SI pin.

A high-to-low transition on the is required to end an operation. When ending an internally self-timed operation such as a program or erase cycle, the device will not enter the standby mode until the completion of the operation.

SERIAL CLOCK: This pin is used to provide a clock to the device and is used to control the flow of data to and from the device. Command, address, and input data present on the SI pin is always latched on the rising edge of SCK, while output data on the SO pin is always clocked out on the falling edge of SCK.

SERIAL INPUT: The SI pin is used to shift data into the device. The SI pin is used for all data input including command and address sequences. Data on the SI pin is always latched on the rising edge of SCK.

CS pin selects the device. When the CS pin is deasserted, the

CS pin is required to start an operation, and a low-to-high transition

AT26DF081A

Asserted

State Type

Low Input

Input

HOLD

GND

SERIAL OUTPUT: The SO pin is used to shift data out from the device. Data on the SO pin is always clocked out on the falling edge of SCK.

WRITE PROTECT: The section “Protection Commands and Features” on page 15 for more details on protection features and the

The not be used. However, it is recommended that the whenever possible.

HOLD: The resetting the device. While the SI pin will be ignored, and the SO pin will be in a high-impedance state.

The condition to start. A Hold condition pauses serial communication only and does not have an effect on internally self-timed operations such as a program or erase cycle. Please refer to section “Hold”

on page 30 for additional details on the Hold operation.

The However, it is recommended that the possible.

DEVICE POWER SUPPLY: The VCCpin is used to supply the source voltage to the device. Operations at invalid V

GROUND: The ground reference for the power supply. GND should be connected to the system ground.

WP pin.

WP pin is internally pulled-high and may be left floating if hardware-controlled protection will

HOLD pin is used to temporarily pause serial communication without deselecting or

CS pin must be asserted, and the SCK pin must be in the low state in order for a Hold

HOLD pin is internally pulled-high and may be left floating if the Hold function will not be used.

WP pin controls the hardware locking feature of the device. Please refer to

WP pin also be externally connected to V

HOLD pin is asserted, transitions on the SCK pin and data on the

HOLD pin also be externally connected to VCCwhenever

voltages may produce spurious results and should not be attempted.

Output

Low Input

Power

3600H–DFLASH–11/2012

3. Block Diagram

Figure 2-1. 8-SOIC Top View

CS SO

GND

2 3 4

8 7 6 5

VCC HOLD SCK SI

SCK

INTERFACE

CONTROL

4. Memory Array

CONTROL AND

PROTECTION LOGIC

I/O BUFFERS

AND LATCHES

SRAM

DATA BUFFER

AND

LOGIC

Y-DECODER

Y-GATING

FLASH

MEMORY

X-DECODER

ARRAY

ADDRESS LATCH

To provide the greatest flexibility, the memory array of the AT26DF081A can be erased in four levels of granularity including a full chip erase. In addition, the array has been divided into physical sectors of various sizes, of which each sector can be individually protected from program and erase operations. The sizes of the physical sectors are optimized for both code and data storage applications, allowing both code and data segments to reside in their own isolated regions. Figure 4-1 on page 5 illustrates the breakdown of each erase level as well as the breakdown of each physical sector.

AT26DF081A

3600H–DFLASH–11/2012

Figure 4-1. Memory Architecture Diagram

AT26DF081A

Block Erase Detail Page Program Detail

Internal Sectoring fo

Sector Protection Block Erase Block Erase Block Erase Page Program

Function (D8h Command) (52h Command) (20h Command) (02h Command)

32KB

(Sector 18)

8KB

(Sector 17)

8KB

(Sector 16)

16KB

(Sector 15)

64KB

(Sector 14)

• •

•

64KB

(Sector 0)

64KB 32KB 4KB 1-256 Byte

Range

0FFFFFh – 0FF000h 256 Bytes 0FFFFFh – 0FFF00h

0FEFFFh – 0FE000h 256 Bytes 0FFEFFh – 0FFE00h 0FDFFFh – 0FD000h 256 Bytes 0FFDFFh – 0FFD00h 0FCFFFh – 0FC000h 256 Bytes 0FFCFFh – 0FFC00h 0FBFFFh – 0FB000h 256 Bytes 0FFBFFh – 0FFB00h 0FAFFFh – 0FA000h 256 Bytes 0FFAFFh – 0FFA00h

0F9FFFh – 0F9000h 256 Bytes 0FF9FFh – 0FF900h

0F8FFFh – 0F8000h 256 Bytes 0FF8FFh – 0FF800h

0F7FFFh – 0F7000h 256 Bytes 0FF7FFh – 0FF700h

0F6FFFh – 0F6000h 256 Bytes 0FF6FFh – 0FF600h

0F5FFFh – 0F5000h 256 Bytes 0FF5FFh – 0FF500h

0F4FFFh – 0F4000h 256 Bytes 0FF4FFh – 0FF400h

0F3FFFh – 0F3000h 256 Bytes 0FF3FFh – 0FF300h

0F2FFFh – 0F2000h 256 Bytes 0FF2FFh – 0FF200h

0F1FFFh – 0F1000h 256 Bytes 0FF1FFh – 0FF100h

0F0FFFh – 0F0000h 256 Bytes 0FF0FFh – 0FF000h 0EFFFFh – 0EF000h 256 Bytes 0FEFFFh – 0FEF00h 0EEFFFh – 0EE000h 256 Bytes 0FEEFFh – 0FEE00h 0EDFFFh – 0ED000h 256 Bytes 0FEDFFh – 0FED00h 0ECFFFh – 0EC000h 256 Bytes 0FECFFh – 0FEC00h 0EBFFFh – 0EB000h 256 Bytes 0FEBFFh – 0FEB00h 0EAFFFh – 0EA000h 256 Bytes 0FEAFFh – 0FEA00h

0E9FFFh – 0E9000h 256 Bytes 0FE9FFh – 0FE900h

0E8FFFh – 0E8000h 256 Bytes 0FE8FFh – 0FE800h

0E7FFFh – 0E7000h

0E6FFFh – 0E6000h

0E5FFFh – 0E5000h

0E4FFFh – 0E4000h 256 Bytes 0017FFh – 001700h

0E3FFFh – 0E3000h 256 Bytes 0016FFh – 001600h

0E2FFFh – 0E2000h 256 Bytes 0015FFh – 001500h

0E1FFFh – 0E1000h 256 Bytes 0014FFh – 001400h

0E0FFFh – 0E0000h 256 Bytes 0013FFh – 001300h

00FFFFh – 00F000h 256 Bytes 000FFFh – 000F00h

00EFFFh – 00E000h 256 Bytes 000EFFh – 000E00h 00DFFFh – 00D000h 256 Bytes 000DFFh – 000D00h 00CFFFh – 00C000h 256 Bytes 000CFFh – 000C00h

00BFFFh – 00B000h 256 Bytes 000BFFh – 000B00h

00AFFFh – 00A000h 256 Bytes 000AFFh – 000A00h

009FFFh – 009000h 256 Bytes 0009FFh – 000900h 008FFFh – 008000h 256 Bytes 0008FFh – 000800h 007FFFh – 007000h 256 Bytes 0007FFh – 000700h 006FFFh – 006000h 256 Bytes 0006FFh – 000600h 005FFFh – 005000h 256 Bytes 0005FFh – 000500h 004FFFh – 004000h 256 Bytes 0004FFh – 000400h 003FFFh – 003000h 256 Bytes 0003FFh – 000300h 002FFFh – 002000h 256 Bytes 0002FFh – 000200h 001FFFh – 001000h 256 Bytes 0001FFh – 000100h 000FFFh – 000000h 256 Bytes 0000FFh – 000000h

•

• •

256 Bytes 0012FFh – 001200h 256 Bytes 0011FFh – 001100h 256 Bytes 0010FFh – 001000h

64KB

4KB 4KB 4KB

32KB

• • •

32KB

• •

•

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 4KB 4KB 4KB 4KB 4KB 4KB 4KB 4KB 4KB 4KB 4KB 4KB 4KB

•

• •

Page AddressBlock Address

Range

3600H–DFLASH–11/2012

5. Device Operation

The AT26DF081A 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 AT26DF081A via the SPI bus which is comprised of four signal lines: Chip Select ( Input (SI), and Serial Output (SO).

The SPI protocol defines a total of four modes of operation (mode 0, 1, 2, or 3) with each mode differing in respect to the SCK polarity and phase and how the polarity and phase control the flow of data on the SPI bus. The AT26DF081A 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

SCK

CS), Serial Clock (SCK), Serial

MSBLSB

6. Commands and Addressing

A valid instruction or operation must always be started by first asserting the CS pin. After the CS pin has been asserted, the SPI Master must then clock out a valid 8-bit opcode on the SPI bus. Following the opcode, instruction dependent information such as address and data bytes would then be clocked out by the SPI Master. All opcode, address, and data bytes are transferred with the most significant bit (MSB) first. An operation is ended by deasserting the CS pin.

Opcodes not supported by the AT26DF081A will be ignored by the device and no operation will be started. The device will continue to ignore any data presented on the SI pin until the start of the next operation (CS pin being deasserted and then reasserted). In addition, if the CSpinis deasserted before complete opcode and address information is sent to the device, then no operation will be performed and the device will simply return to the idle state and wait for the next operation.

Addressing of the device requires a total of three bytes of information to be sent, representing address bits A23 - A0. Since the upper address limit of the AT26DF081A memory array is 0FFFFFh, address bits A23 - A20 are always ignored by the device.

MSB

LSB

AT26DF081A

3600H–DFLASH–11/2012

AT26DF081A

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+

Program and Erase Commands

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

Chip Erase

Byte/Page Program (1 to 256 Bytes) 02h 0000 0010 3 0 1+

Sequential Program Mode

Protection Commands

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

Global Protect/Unprotect Use Write Status Register command

Read Sector Protection Registers 3Ch 0011 1100 3 0 1+

Status Register Commands

Read Status Register 05h 0000 0101 0 0 1+

Write Status Register 01h 0000 0001 0 0 1

Miscellaneous Commands

Read Manufacturer and Device ID 9Fh 1001 1111 0 0 1 to 4

Deep Power-down B9h 1011 1001 0 0 0

60h 0110 0000 0 0 0

C7h 1100 0111 0 0 0

ADh 1010 1101 3, 0

AFh 1010 1111 3, 0

(1)

Resume from Deep Power-down ABh 1010 1011 0 0 0

Note: 1. Three address bytes are only required for the first operation to designate the address to start programming at. Afterwards,

the internal address counter automatically increments, so subsequent Sequential Program Mode operations only require clocking in of the opcode and the data byte until the Sequential Program Mode has been exited.

3600H–DFLASH–11/2012

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 f opcode can be used for lower frequency read operations up to the maximum specified by f

To perform the Read Array operation, the 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 (0FFFFFh) of the memory array has been read, the device will continue reading back at the beginning of the array (000000h). No delays will be incurred when wrapping around from the end of the array to the beginning of the array.

.The03h

SCK

RDLF

CS pin must first be asserted and the appropriate

Deasserting the ance 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

SCK

2 310

OPCODE

00001011

MSB MSB

HIGH-IMPEDANCE

CS pin will terminate the read operation and put the SO pin into a high-imped-

6754101198 12 39 42 43414037 3833 36353431 3229304447484645

ADDRESS BITS A23-A0 DON'T CARE

AAAA AAAA A

XXXXXXXX

MSB

DATA BYTE 1

DDDDDDDDDD

MSBMSB

AT26DF081A

3600H–DFLASH–11/2012

Figure 7-2. Read Array – 03h Opcode

AT26DF081A

SCK

2 310

OPCODE

00000011

MSB MSB

HIGH-IMPEDANCE

6754101198 12 37 3833 36353431 322930 39 40

8. Program and Erase Commands

8.1 Byte/Page Program

The Byte/Page Program command allows anywhere from a single byte of data to 256 bytes of data to be programmed into previously erased memory locations. An erased memory location is one that has all eight bits set to the logical “1” state (a byte value of FFh). Before a Byte/Page Program command can be started, the Write Enable command must have been previously issued to the device (see “Write Enable” on page 15 command description) to set the Write Enable Latch (WEL) bit of the Status Register to a logical “1” state.

To perform a Byte/Page Program command, an opcode of 02h must be clocked into the device followed by the three address bytes denoting the first byte location of the memory array to begin programming at. After the address bytes have been clocked in, data can then be clocked into the device and will be stored in an internal buffer.

ADDRESS BITS A23-A0

AAAA AAAA A

DATA BYTE 1

DDDDDDDDDD

MSBMSB

If the starting memory address denoted by A23 - A0 does not fall on an even 256-byte page boundary (A7 - A0 are not all 0’s), then special circumstances regarding which memory locations will be programmed will apply. In this situation, any data that is sent to the device that goes beyond the end of the page will wrap around back to the beginning of the same page. For example, if the starting address denoted by A23 - A0 is 0000FEh, and three bytes of data are sent to the device, then the first two bytes of data will be programmed at addresses 0000FEh and 0000FFh while the last byte of data will be programmed at address 000000h. The remaining bytes in the page (addresses 000001h through 0000FDh) will be unaffected and will not change. In addition, if more than 256 bytes of data are sent to the device, then only the last 256 bytes sent will be latched into the internal buffer.

When the CS pin is deasserted, the device will take the data stored in the internal buffer and program it into the appropriate memory array locations based on the starting address specified by A23 - A0 and the number of data bytes sent to the device. If less than 256 bytes of data were sent to the device, then the remaining bytes within the page will not be altered. The programming of the data bytes is internally self-timed and should take place in a time of tPP.

The three address bytes and at least one complete byte of data must be clocked into the device before the CS pin is deasserted, and the CS pin must be deasserted on even byte boundaries (multiples of eight bits); otherwise, the device will abort the operation and no data will be programmed into the memory array. In addition, if the address specified by A23 - A0 points to a memory location within a sector that is in the protected state (see section “Protect Sector” on

page 16), then the Byte/Page Program command will not be executed, and the device will return

to the idle state once the CS pin has been deasserted. The WEL bit in the Status Register will be

3600H–DFLASH–11/2012

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 tPPtime to determine if the data bytes have finished programming. At some point before the program cycle completes, the WEL bit in the Status Register will be reset back to the logical “0” state.

The device also incorporates an intelligent programming algorithm that can detect when a byte location fails to program properly. If a programming error arises, it will be indicated by the EPE bit in the Status Register.

The Byte/Page Program mode is the default programming mode after the device powers-up or resumes from a device reset.

Figure 8-1. Byte Program

SCK

Figure 8-2. Page Program

SCK

00000010

MSB MSB

HIGH-IMPEDANCE

2 310

OPCODE

00000010

MSB MSB

HIGH-IMPEDANCE

2 310

OPCODE

6754 983937 3833 36353431 322930

ADDRESS BITS A23-A0 DATA IN BYTE 1

AA AAAA

6754101198 12 3937 3833 36353431 322930

ADDRESS BITS A23-A0 DATA IN

AAAA AAAA A

DDDDDDDD

MSB

DDDDDDDD

MSB

DATA IN BYTE n

DDDDDDDD

MSB

AT26DF081A

3600H–DFLASH–11/2012

8.2 Sequential Program Mode

The Sequential Program Mode improves throughput over the Byte/Page Program command when the Byte/Page Program command is used to program single bytes only into consecutive address locations. For example, some systems may be designed to program only a single byte of information at a time and cannot utilize a buffered Page Program operation due to design restrictions. In such a case, the system would normally have to perform multiple Byte Program operations in order to program data into sequential memory locations. This approach can add considerable system overhead and SPI bus traffic.

The Sequential Programming Mode helps reduce system overhead and bus traffic by incorporating an internal address counter that keeps track of the byte location to program, thereby eliminating the need to supply an address sequence to the device for every byte to program. When using the Sequential Program mode, all address locations to be programmed must be in the erased state. Before the Sequential Program mode can first be entered, the Write Enable command must have been previously issued to the device to set the WEL bit of the Status Register to a logical “1” state.

AT26DF081A

To start the Sequential Program Mode, the of ADh or AFh must be clocked into the device. For the first program cycle, three address bytes must be clocked in after the opcode to designate the first byte location to program. After the address bytes have been clocked in, the byte of data to be programmed can be sent to the device. Deasserting the CS pin will start the internally self-timed program operation, and the byte of data will be programmed into the memory location specified by A23 - A0.

After the first byte has been successfully programmed, a second byte can be programmed by simply reasserting the CS pin, clocking in the ADh or AFh opcode, and then clocking in the next byte of data. When the 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 Program Mode has been entered.

When the last desired byte has been programmed into the memory array, the Sequential Program Mode operation can be terminated by reasserting the 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 last byte of data sent on the SI pin will be stored in the internal latches. The programming of each byte is internally self-timed and should take place in a time of tBP. For each program cycle, a complete byte of data must be clocked into the device before the CS pin is deasserted, and the CS pin must be deasserted on even byte boundaries (multiples of eight bits); otherwise, the device will abort the operation, the byte of data will not be programmed into the memory array, and the WEL bit in the Status Register will be reset back to the logical “0” state.

CS pin must first be asserted, and either an opcode

3600H–DFLASH–11/2012

If the address initially specified by A23 - A0 points to a memory location within a sector that is in the protected state, then the Sequential Program Mode command will not be executed, and the device will return to the idle state once the CS pin has been deasserted. The WEL bit in the Status Register will also be reset back to the logical “0” state.

There is no address wrapping when using the Sequential Program Mode. Therefore, when the last byte (0FFFFFh) of the memory array has been programmed, the device will automatically exit the Sequential Program mode and reset the WEL bit in the Status Register back to the logical “0” state. In addition, the Sequential Program mode will not automatically skip over protected

sectors; therefore, once the highest unprotected memory location in a programming sequence has been programmed, the device will automatically exit the Sequential Program mode and reset the WEL bit in the Status Register. For example, if Sector 1 was protected and Sector 0 was currently being programmed, once the last byte of Sector 0 was programmed, the Sequential Program mode would automatically end. To continue programming with Sector 2, the Sequential Program mode would have to be restarted by supplying the ADh or AFh opcode, the three address bytes, and the first byte of Sector 2 to program.

While the device is programming a byte, the Status Register can be read and will indicate that the device is busy. For faster throughput, it is recommended that the Status Register be polled at the end of each program cycle rather than waiting the tBPtime to determine if the byte has finished programming before starting the next Sequential Program mode cycle.

Figure 8-3. Sequential Program Mode – Status Register Polling

Seqeuntial Program Mode

Command

Opcode

Note: Each transition shown for SI represents one byte (8 bits)

A23-16 A15-8 A7-0 05hData

First Address to Program

HIGH-IMPEDANCE

Status Register Read

Command

STATUS REGISTER

Seqeuntial Program Mode

Command

Opcode

DATA

Seqeuntial Program Mode

Data 05h 04h

STATUS REGISTER

DATA

Figure 8-4. Sequential Program Mode – Waiting Maximum Byte Program Time

Seqeuntial Program Mode

Command

Opcode

Note: Each transition shown for SI represents one byte (8 bits)

A23-16 A15-8 A7-0 Data

First Address to Program

HIGH-IMPEDANCE

Seqeuntial Program Mode

Command

Opcode

Data 04h

Seqeuntial Program Mode

Command

Opcode

Data 05h

Data

Write Disable

Command

STATUS REGISTER

Write Disable

Command

DATA

AT26DF081A

3600H–DFLASH–11/2012

8.3 Block Erase

AT26DF081A

A block of 4, 32, or 64 Kbytes can be erased (all bits set to the logical “1” state) in a single operation by using one of three different opcodes for the Block Erase command. An opcode of 20h is used for a 4-Kbyte erase, an opcode of 52h is used for a 32-Kbyte erase, and an opcode of D8h is used for a 64-Kbyte erase. Before a Block Erase command can be started, the Write Enable command must have been previously issued to the device to set the WEL bit of the Status Register to a logical “1” state.

To perform a Block Erase, the CS pin must first be asserted and the appropriate opcode (20h, 52h or D8h) must be clocked into the device. After the opcode has been clocked in, the three address bytes specifying an address within the 4-, 32-, or 64-Kbyte block to be erased must be clocked in. Any additional data clocked into the device will be ignored. When the CS pin is deasserted, the device will erase the appropriate block. The erasing of the block is internally selftimed and should take place in a time of t

Since the Block Erase command erases a region of bytes, the lower order address bits do not need to be decoded by the device. Therefore, for a 4-Kbyte erase, address bits A11 - A0 will be ignored by the device and their values can be either a logical “1” or “0”. For a 32-Kbyte erase, address bits A14 - A0 will be ignored, and for a 64-Kbyte erase, address bits A15 - A0 will be ignored by the device. Despite the lower order address bits not being decoded by the device, the complete three address bytes must still be clocked into the device before the CS pin is deasserted, and the CS pin must be deasserted on an even byte boundary (multiples of eight bits); otherwise, the device will abort the operation and no erase operation will be performed.

BLKE

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 32K and 64 Kbytes, more than one physical sector may be erased (e.g. sectors 18 through 15) at one time. Therefore, in order to erase a larger block that may span more than one sector, all of the sectors in the span must be in the unprotected state. If one of the physical sectors within the span is in the protected state, then the device will ignore the Block Erase command and will return to the idle state once the CS pin is deasserted.

The WEL bit in the Status Register will be reset back to the logical “0” state if the erase cycle aborts due to an incomplete address being sent or because a memory location within the region to be erased is protected.

While the device is executing a successful erase cycle, the Status Register can be read and will indicate that the device is busy. For faster throughput, it is recommended that the Status Register be polled rather than waiting the t some point before the erase cycle completes, the WEL bit in the Status Register will be reset back to the logical “0” state.

The device also incorporates an intelligent erasing algorithm that can detect when a byte location fails to erase properly. If an erase error occurs, it will be indicated by the EPE bit in the Status Register.

time to determine if the device has finished erasing. At

BLKE

3600H–DFLASH–11/2012

Figure 8-5. Block Erase

8.4 Chip Erase

2 310

6754101198 12 31293027 2826

SCK

OPCODE

CCCCCCCC

MSB MSB

HIGH-IMPEDANCE

AAAA AAAA A A A A

ADDRESS BITS A23-A0

The entire memory array can be erased in a single operation by using the Chip Erase command. Before a Chip Erase command can be started, the Write Enable command must have been previously issued to the device to set the WEL bit of the Status Register to a logical “1” state.

Two opcodes, 60h and C7h, can be used for the Chip Erase command. There is no difference in device functionality when utilizing the two opcodes, so they can be used interchangeably. To perform a Chip Erase, one of the two opcodes (60h or C7h) must be clocked into the device. Since the entire memory array is to be erased, no address bytes need to be clocked into the device, and any data clocked in after the opcode will be ignored. When the CS pin is deasserted, the device will erase the entire memory array. The erasing of the device is internally self-timed and should take place in a time of t

CHPE

The complete opcode must be clocked into the device before the CS pin is deasserted, and the CS pin must be deasserted on an even byte boundary (multiples of eight bits); otherwise, 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.

AT26DF081A

time to determine if the device has finished erasing. At

CHPE

3600H–DFLASH–11/2012

Figure 8-6. Chip Erase

AT26DF081A

SCK

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, and the CS pin must be deasserted on an even byte boundary (multiples of eight bits); otherwise, the device will abort the operation and the state of the WEL bit will not change.

2 310

OPCODE

CCCCCCCC

MSB

HIGH-IMPEDANCE

6754

3600H–DFLASH–11/2012

Figure 9-1. Write Enable

SCK

2 310

OPCODE

00000110

MSB

HIGH-IMPEDANCE

6754

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 section of the Status Register description.

9.3 Protect Sector

To issue the Write Disable command, the

CS pin must first be asserted and the opcode of 04h must be clocked into the device. No address bytes need to be clocked into the device, and any data clocked in after the opcode will be ignored. When the CS pin is deasserted, the WEL bit in the Status Register will be reset to a logical “0”. The complete opcode must be clocked into the device before the

CS pin is deasserted, and the CS pin must be deasserted on an even byte boundary (multiples of eight bits); otherwise, the device will abort the operation and the state of the WEL bit will not change.

Figure 9-2. Write Disable

2 310

6754

SCK

OPCODE

00000100

MSB

HIGH-IMPEDANCE

Every physical sector of the device has a corresponding single-bit Sector Protection Register that is used to control the software protection of a sector. Upon device power-up or after a device reset, each Sector Protection Register will default to the logical “1” state indicating that all sectors are protected and cannot be programmed or erased.

Issuing the Protect Sector command to a particular sector address will set the corresponding Sector Protection Register to the logical “1” state. The following table outlines the two states of the Sector Protection Registers.

Table 9-1. Sector Protection Register Values

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

AT26DF081A

3600H–DFLASH–11/2012

AT26DF081A

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 serted, and the

CS pin must be deasserted on an even byte boundary (multiples of eight bits);

CS pin is deas-

otherwise, the device will abort the operation, the state of the Sector Protection Register will be unchanged, and the WEL bit in the Status Register will be reset to a logical “0”.

As a safeguard against accidental or erroneous protecting or unprotecting of sectors, the Sector Protection Registers can themselves be locked from updates by using the SPRL (Sector Protection Registers Locked) bit of the Status Register (please refer to the Status Register description for more details). If the Sector Protection Registers are locked, then any attempts to issue the Protect Sector command will be ignored, and the device will reset the WEL bit in the Status Register back to a logical “0” and return to the idle state once the CS pin has been deasserted.

Figure 9-3. Protect Sector

SCK

2 310

OPCODE

00110110

MSB MSB

HIGH-IMPEDANCE

6754101198 12 31293027 2826

ADDRESS BITS A23-A0

AAAA AAAA A A A A

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, and the CS pin must be deasserted on an even byte boundary (multiples of eight bits); otherwise, the device will abort the operation, the state of the Sector Protection Register will be unchanged, and the WEL bit in the Status Register will be reset to a logical “0”.

As a safeguard against accidental or erroneous locking or unlocking of sectors, the Sector Protection Registers can themselves be locked from updates by using the SPRL (Sector Protection Registers Locked) bit of the Status Register (please refer to the Status Register description for more details). If the Sector Protection Registers are locked, then any attempts to issue the

3600H–DFLASH–11/2012

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

9.5 Global Protect/Unprotect

The Global Protect and Global Unprotect features can work in conjunction with the Protect Sector and Unprotect Sector functions. For example, a system can globally protect the entire memory array and then use the Unprotect Sector command to individually unprotect certain sectors and individually reprotect them later by using the Protect Sector command. Likewise, a system can globally unprotect the entire memory array and then individually protect certain sectors as needed.

Performing a Global Protect or Global Unprotect is accomplished by writing a certain combination of data to the Status Register using the Write Status Register command (see “Write Status Register” section on page 26 for command execution details). The Write Status Register command is also used to modify the SPRL (Sector Protection Registers Locked) bit to control hardware and software locking.

To perform a Global Protect, the appropriate WP pin and SPRL conditions must be met, and the system must write a logical “1” to bits 5, 4, 3, and 2 of the Status Register. Conversely, to perform a Global Unprotect, the same WP and SPRL conditions must be met but the system must write a logical “0” to bits 5, 4, 3, and 2 of the Status Register. Table 9-2 details the conditions necessary for a Global Protect or Global Unprotect to be performed.

SCK

2 310

OPCODE

00111001

MSB MSB

HIGH-IMPEDANCE

6754101198 12 31293027 2826

ADDRESS BITS A23-A0

AAAA AAAA A A A A

AT26DF081A

3600H–DFLASH–11/2012

Table 9-2. Valid SPRL and Global Protect/Unprotect Conditions

New

Write Status

Current

State

SPRL Value

Bit

76543210

0x0000xx 0x0001xx



0x1110xx 0x1111xx

1x0000xx 1x0001xx



1x1110xx 1x1111xx

Protection Operation

Global Unprotect – all Sector Protection Registers reset to 0 No change to current protection. No change to current protection. No change to current protection. Global Protect – all Sector Protection Registers set to 1

No change to the current protection level. All sectors currently protected will remain protected and all sectors currently unprotected will remain unprotected.

AT26DF081A

New SPRL Value

0 0 0 0 0

1 1 1 1 1

0 1 xxxxxxxx

0x0000xx 0x0001xx



0x1110xx 0x1111xx

1x0000xx 1x0001xx



1x1110xx 1x1111xx

0x0000xx 0x0001xx



0x1110xx 0x1111xx

1x0000xx 1x0001xx



1x1110xx 1x1111xx

The Sector Protection Registers are hard-locked and cannot be changed when the WP pin is LOW and the current state of SPRL is 1. Therefore, a Global Protect/Unprotect will not occur. In addition, the SPRL bit cannot be changed (the WP pin must be HIGH in order to change SPRL back to a 0).

No change to the current protection level. All sectors currently protected will remain protected, and all sectors currently unprotected will remain unprotected.

The Sector Protection Registers are soft-locked and cannot be changed when the current state of SPRL is 1. Therefore, a Global Protect/Unprotect will not occur. However, the SPRL bit can be changed back to a 0 from a 1 since the WP pin is HIGH. To perform a Global Protect/Unprotect, the Write Status Register command must be issued again after the SPRL bit has been changed froma1toa0.

0 0 0 0 0

1 1 1 1 1

0 0 0 0 0

1 1 1 1 1

3600H–DFLASH–11/2012

Essentially, if the SPRL bit of the Status Register is in the logical “0” state (Sector Protection Registers are not locked), then writing a 00h to the Status Register will perform a Global Unprotect without changing the state of the SPRL bit. Similarly, writing a 7Fh to the Status Register will perform a Global Protect and keep the SPRL bit in the logical “0” state. The SPRL bit can, of course, be changed to a logical “1” by writing an FFh if software-locking or hardware-locking is desired along with the Global Protect.

If the desire is to only change the SPRL bit without performing a Global Protect or Global Unprotect, then the system can simply write a 0Fh to the Status Register to change the SPRL bit from a logical “1” to a logical “0” provided the F0h to change the SPRL bit from a logical “0” to a logical “1” without affecting the current sector protection status (no changes will be made to the Sector Protection Registers).

When writing to the Status Register, bits 5, 4, 3, and 2 will not actually be modified but will be decoded by the device for the purposes of the Global Protect and Global Unprotect functions. Only bit 7, the SPRL bit, will actually be modified. Therefore, when reading the Status Register, bits 5, 4, 3, and 2 will not reflect the values written to them but will instead indicate the status of the

WP pin and the sector protection status. Please refer to the “Read Status Register” section and Table 10-1 on page 23 for details on the Status Register format and what values can be read for bits 5, 4, 3, and 2.

9.6 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.

WP pin is deasserted. Likewise, the system can write an

Table 9-3. Read Sector Protection Register – Output Data

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 to the “Status Register Commands” on page 23 for more details).

AT26DF081A

3600H–DFLASH–11/2012

Figure 9-5. Read Sector Protection Register

AT26DF081A

2 310

6754101198 12 37 3833 36353431 322930 39 40

SCK

OPCODE

00111100

MSB MSB

HIGH-IMPEDANCE

ADDRESS BITS A23-A0

AAAA AAAA A

9.7 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 using the Write Status Register command. When resetting the SPRL bit back to a logical “0”, it is not possible to perform a Global Protect or Global Unprotect at the same time since the Sector Protection Registers remain soft-locked until after the Write Status Register command has been executed.

DATA BYTE

DDDDDDDDDD

MSBMSB

3600H–DFLASH–11/2012

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. When changing the SPRL bit to a logical “1” from a logical “0”, it is also possible to perform a Global Protect or Global Unprotect at the same time by writing the appropriate values into bits 5, 4, 3, and 2 of the Status Register.

Tables 9-4 and 9-5 detail the various protection and locking states of the device.

Table 9-4. Sector Protection Register States

Sector Protection Register

(Don't Care)

Note: 1. “n” represents a sector number

n(1)

0 Unprotected

1 Protected

Sector

n(1)

Table 9-5. Hardware and Software Locking

WP SPRL Locking SPRL Change Allowed Sector Protection Registers

Unlocked and modifiable using

0 0 Can be modified from 0 to 1

1 0 Can be modified from 0 to 1

Hardware

Locked

Software

Locked

Can be modified from 1 to 0

the Protect and Unprotect Sector commands. Global Protect and Unprotect can also be performed.

Locked in current state. Protect and Unprotect Sector commands will be ignored. Global Protect and Unprotect cannot be performed.

Unlocked and modifiable using the Protect and Unprotect Sector commands. Global Protect and Unprotect can also be performed.

Locked in current state. Protect and Unprotect Sector commands will be ignored. Global Protect and Unprotect cannot be performed.

AT26DF081A

3600H–DFLASH–11/2012

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.

AT26DF081A

To read the Status Register, the clocked into the device. After the last bit of the opcode has been clocked in, the device will begin outputting Status Register data on the SO pin during every subsequent clock cycle. After the last bit (bit 0) of the Status Register has been clocked out, the sequence will repeat itself starting again with bit 7 as long as the data in the Status Register is constantly being updated, so each repeating sequence will output new data.

Deasserting the

CS pin will terminate the Read Status Register operation and put the SO pin into a high-impedance state. The CS pin can be deasserted at any time and does not require that a full byte of data be read.

Table 10-1. Status Register Format

(1)

Bit

7 SPRL Sector Protection Registers Locked R/W

6 SPM Sequential Program Mode Status R

5 EPE Erase/Program Error R

4 WPP Write Protect (

Name Type

WP) Pin Status R

CS pin must first be asserted and the opcode of 05h must be

CS pin remains asserted and the SCK pin is being pulsed. The

(2)

Description

0 Sector Protection Registers are unlocked (default).

1 Sector Protection Registers are locked.

0 Byte/Page Programming Mode (default).

1 Sequential Programming Mode entered.

0 Erase or program operation was successful.

1 Erase or program error detected.

WP is asserted.

WP is deasserted.

All sectors are software unprotected (all Sector

Protection Registers are 0).

Some sectors are software protected. Read individual

3:2 SWP Software Protection Status R

1 WEL Write Enable Latch Status R

0 RDY/BSY Ready/Busy Status R

Notes: 1. Only bit 7 of the Status Register will be modified when using the Write Status Register command.

2. R/W = Readable and writable R = Readable only

3600H–DFLASH–11/2012

Sector Protection Registers to determine which sectors are protected.

10 Reserved for future use.

All sectors are software protected (all Sector

Protection Registers are 1 – default).

0 Device is not write enabled (default).

1 Device is write enabled.

0 Device is ready.

1 Device is busy with an internal operation.

10.1.1 SPRL Bit

10.1.2 SPM Bit

The SPRL bit is used to control whether the Sector Protection Registers can be modified or not. When the SPRL bit is in the logical “1” state, all Sector Protection Registers are locked and cannot be modified with the Protect Sector and Unprotect Sector commands (the device will ignore these commands). In addition, the Global Protect and Global Unprotect features cannot be performed. Any sectors that are presently protected will remain protected, and any sectors that are presently unprotected will remain unprotected.

When the SPRL bit is in the logical “0” state, all Sector Protection Registers are unlocked and can be modified (the Protect Sector and Unprotect Sector commands, as well as the Global Protect and Global Unprotect features, will be processed as normal). The SPRL bit defaults to the logical “0” state after a power-up or a device reset.

The SPRL bit can be modified freely whenever the WP pin is deasserted. However, if the WP pin is asserted, then the SPRL bit may only be changed from a logical “0” (Sector Protection Registers are unlocked) to a logical “1” (Sector Protection Registers are locked). In order to reset the SPRL bit back to a logical “0” using the Write Status Register command, the WP pin will have to first be deasserted.

The SPRL bit is the only bit of the Status Register that can be user modified via the Write Status Register command.

The SPM bit indicates whether the device is in the Byte/Page Program mode or the Sequential Program Mode. The default state after power-up or device reset is the Byte/Page Program mode.

10.1.3 EPE Bit

10.1.4 WPP Bit

10.1.5 SWP Bits

The EPE bit indicates whether the last erase or program operation completed successfully or not. If at least one byte during the erase or program operation did not erase or program properly, then the EPE bit will be set to the logical “1” state. The EPE bit will not be set if an erase or program operation aborts for any reason such as an attempt to erase or program a protected region or if the WEL bit is not set prior to an erase or program operation. The EPE bit will be updated after every erase and program operation.

The WPP bit can be read to determine if the WP pin has been asserted or not.

The SWP bits provide feedback on the software protection status for the device. There are three possible combinations of the SWP bits that indicate whether none, some, or all of the sectors have been protected using the Protect Sector command or the Global Protect feature. If the SWP bits indicate that some of the sectors have been protected, then the individual Sector Protection Registers can be read with the Read Sector Protection Registers command to determine which sectors are in fact protected.

AT26DF081A

3600H–DFLASH–11/2012

10.1.6 WEL Bit

AT26DF081A

The WEL bit indicates the current status of the internal Write Enable Latch. When the WEL bit is in the logical “0” state, the device will not accept any program, erase, Protect Sector, Unprotect Sector, or Write Status Register commands. The WEL bit defaults to the logical “0” state after a device power-up or reset. In addition, the WEL bit will be reset to the logical “0” state automatically under the following conditions:

• Write Disable operation completes successfully

• Write Status Register operation completes successfully or aborts

• Protect Sector operation completes successfully or aborts

• Unprotect Sector operation completes successfully or aborts

• Byte/Page Program operation completes successfully or aborts

• Sequential Program Mode reaches highest unprotected memory location

• Sequential Program Mode reaches the end of the memory array

• Sequential Program Mode aborts

• Block Erase operation completes successfully or aborts

• Chip Erase operation completes successfully or aborts

• Hold condition aborts

10.1.7 RDY/BSY Bit

If the WEL bit is in the logical “1” state, it will not be reset to a logical “0” if an operation aborts due to an incomplete or unrecognized opcode being clocked into the device before the CS pin is deasserted. In order for the WEL bit to be reset when an operation aborts prematurely, the entire opcode for a program, erase, Protect Sector, Unprotect Sector, or Write Status Register command must have been clocked into the device.

The RDY/BSY bit is used to determine whether or not an internal operation, such as a program or erase, is in progress. To poll the RDY/BSY bit to detect the completion of a program or erase cycle, new Status Register data must be continually clocked out of the device until the state of the RDY/BSY bit changes from a logical “1” to a logical “0”.

Figure 10-1. Read Status Register

2 310

6754101198 12 21 2217 20191815 1613 14 23 24

SCK

OPCODE

00000101

MSB

HIGH-IMPEDANCE

STATUS REGISTER DATA STATUS REGISTER DATA

DDDDDD DDDD

MSB MSB

DDDDDDDD

MSB

3600H–DFLASH–11/2012

10.2 Write Status Register

The Write Status Register command is used to modify the SPRL bit of the Status Register and/or to perform a Global Protect or Global Unprotect operation. Before the Write Status Register command can be issued, the Write Enable command must have been previously issued to set the WEL bit in the Status Register to a logical “1”.

To issue the Write Status Register command, the

CS pin must first be asserted and the opcode of 01h must be clocked into the device followed by one byte of data. The one byte of data consists of the SPRL bit value, a don’t care bit, four data bits to denote whether a Global Protect or Unprotect should be performed, and two additional don’t care bits (see Table 10-2). Any additional data bytes that are sent to the device will be ignored. When the CS pin is deasserted, the SPRL bit in the Status Register will be modified, and the WEL bit in the Status Register will be reset back to a logical “0”. The values of bits 5, 4, 3, and 2 and the state of the SPRL bit before the Write Status Register command was executed (the prior state of the SPRL bit) will determine whether or not a Global Protect or Global Unprotect will be performed. Please refer to the “Global Protect/Unprotect” section on page 18 for more details.

The complete one byte of data must be clocked into the device before the CS pin is deasserted; otherwise, the device will abort the operation, the state of the SPRL bit will not change, no potential Global Protect or Unprotect will be performed, and the WEL bit in the Status Register will be reset back to the logical “0” state.

If the WP pin is asserted, then the SPRL bit can only be set to a logical “1”. If an attempt is made to reset the SPRL bit to a logical “0” while the WP pin is asserted, then the Write Status Register command will be ignored, and the WEL bit in the Status Register will be reset back to the logical “0” state. In order to reset the SPRL bit to a logical “0”, the WP pin must be deasserted.

Table 10-2. Write Status Register Format

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

SPRL X Global Protect/Unprotect X X

Figure 10-2. Write Status Register

AT26DF081A

SCK

2310

OPCODE

0000000

MSB

HIGH-IMPEDANCE

675410119814151312

STATUS REGISTER IN

1DXDDDDXX

MSB

3600H–DFLASH–11/2012

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.

AT26DF081A

To read the identification information, the must be clocked into the device. After the opcode has been clocked in, the device will begin outputting the identification data on the SO pin during the subsequent clock cycles. The first byte that will be output will be the Manufacturer ID followed by two bytes of Device ID information. The fourth byte output will be the Extended Device Information String Length, which will be 00h indicating that no Extended Device Information follows. After the Extended Device Information String Length byte is output, the SO pin will go into a high-impedance state; therefore, additional clock cycles will have no affect on the SO pin and no data will be output. As indicated in the JEDEC standard, reading the Extended Device Information String Length and any subsequent data is optional.

Deasserting the CS pin will terminate the Manufacturer and Device ID read operation and put the SO pin into a high-impedance state. The CS pin can be deasserted at any time and does not require that a full byte of data be read.

Table 11-1. Manufacturer and Device ID Information

Byte No. Data Type Value

1 Manufacturer ID 1Fh

2 Device ID (Part 1) 45h

3 Device ID (Part 2) 01h

4 Extended Device Information String Length 00h

CS pin must first be asserted and the opcode of 9Fh

Table 11-2. Manufacturer and Device ID Details

Data Type Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

JEDEC Assigned Code

Manufacturer ID

00011111

Family Code Density Code

Device ID (Part 1)

01000101

MLC Code Product Version Code

Device ID (Part 2)

00000001

3600H–DFLASH–11/2012

Hex

Value Details

1Fh JEDEC Code: 0001 1111 (1Fh for Adesto®)

45h

01h

Family Code: 010 (AT26DFxxx series) Density Code: 00101 (8-Mbit)

MLC Code: 000 (1-bit/cell technology) Product Version:00001 (First major revision)

Figure 11-1. Read Manufacturer and Device ID

87 38

14 1615 22 2423 30 3231

SCK

OPCODE

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 t

The complete opcode must be clocked in before the CS pin is deasserted, and the CS pin must be deasserted on an even byte boundary (multiples of eight bits); otherwise, the device will abort the operation and return to the standby mode once the CS pin is deasserted. In addition, the device will default to the standby mode after a power-cycle or a device reset.

HIGH-IMPEDANCE

Note: Each transition shown for SI and SO represents one byte (8 bits)

9Fh

1Fh

MANUFACTURER ID DEVICE ID

BYTE 1

45h 01h 00h

EDPD

DEVICE ID

BYTE 2

EXTENDED

DEVICE

INFORMATION

STRING LENGTH

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.

AT26DF081A

3600H–DFLASH–11/2012

Figure 11-2. Deep Power-down

AT26DF081A

SCK

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 t has returned to the standby mode, normal command operations such as Read Array can be resumed.

2310

OPCODE

10111001

MSB

HIGH-IMPEDANCE

Active Current

Standby Mode Current

RDPD

EDPD

6754

Deep Power-Down Mode Current

and return to the standby mode. After the device

If the complete opcode is not clocked in before the CS pin is deasserted, or if the CS pin is not deasserted on an even byte boundary (multiples of eight bits), then the device will abort the operation and return to the Deep Power-down mode.

Figure 11-3. Resume from Deep Power-down

RDPD

2310

6754

SCK

OPCODE

10101011

MSB

HIGH-IMPEDANCE

Active Current

Deep Power-Down Mode Current

Standby Mode Current

3600H–DFLASH–11/2012

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.

Figure 11-4. Hold Mode

SCK

The Hold mode can only be entered while the simply by asserting the the SCK high pulse, then the Hold mode won't be started until the beginning of the next SCK low pulse. The device will remain in the Hold mode as long as the asserted.

While in the Hold mode, the SO pin will be in a high-impedance state. In addition, both the SI pin and the SCK pin will be ignored. The WP pin, however, can still be asserted or deasserted while in the Hold mode.

To end the Hold mode and resume serial communication, the HOLD pin must be deasserted during the SCK low pulse. If the HOLD pin is deasserted during the SCK high pulse, then the Hold mode won't end until the beginning of the next SCK low pulse.

If the CS pin is deasserted while the HOLD pin is still asserted, then any operation that may have been started will be aborted, and the device will reset the WEL bit in the Status Register back to the logical “0” state.

HOLD pin during the SCK low pulse. If the HOLD pin is asserted during

CS pin is asserted. The Hold mode is activated

HOLD pin and CS pin are

HOLD

Hold HoldHold

AT26DF081A

3600H–DFLASH–11/2012

12. Electrical Specifications

12.1 Absolute Maximum Ratings*

Temperature under Bias ................................. -55C to +125C

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 V

+ 0.5V

12.2 DC and AC Operating Range

Operating Temperature (Case) Ind. -40Cto85C

Power Supply 2.7V to 3.6V

*NOTICE: Stresses beyond those listed under “Absolute

Maximum Ratings” may cause permanent dam-

age to the device. This is a stress rating only and

functional operation of the device at these or any

other conditions beyond those indicated in the

operational sections of this specification is not

implied. Exposure to absolute maximum rating

conditions for extended periods may affect device

reliability.

AT26DF081A

12.3 DC Characteristics

Symbol Parameter Condition Min Typ Max Units

DPD

CC1

CC2

CC3

Standby Current

Deep Power-down Current

CS, WP, HOLD = VCC, all inputs at CMOS levels

f = 70 MHz; I

OUT

= 0 mA;

CS = VIL,VCC= Max

f = 66 MHz; I

OUT

= 0 mA;

CS = VIL,VCC= Max

Active Current, Read Operation

f = 50 MHz; I CS = VIL,VCC= Max

f = 33 MHz; I

OUT

= 0 mA;

CS = VIL,VCC= Max

f = 20 MHz; I

OUT

= 0 mA;

CS = VIL,VCC= Max

Active Current, Program Operation CS = VCC,VCC= Max 12 18 mA

Active Current, Erase Operation CS = VCC,VCC= Max 14 20 mA

Input Leakage Current VIN= CMOS levels 1 µA

Output Leakage Current V

= CMOS levels 1 µA

OUT

Input Low Voltage 0.3 x V

Input High Voltage 0.7 x V

Output Low Voltage IOL= 1.6 mA; VCC=Min 0.4 V

Output High Voltage IOH= -100 µA VCC-0.2V V

25 35 µA

11 16

10 15

914

812

710

3600H–DFLASH–11/2012

12.4 AC Characteristics

Symbol Parameter Min Max Units

SCK

RDLF

SCKH

SCKL

(1)

SCKR

(1)

SCKF

CSH

CSLS

CSLH

CSHS

CSHH

(1)

DIS

(2)

HLS

HLH

HHS

HHH

(1)

HLQZ

(1)

HHQX

(1)(3)

WPS

(1)(3)

WPH

(1)

SECP

(1)

SECUP

(1)

EDPD

(1)

RDPD

Notes: 1. Not 100% tested (value guaranteed by design and characterization).

2. 15 pF load at 70 MHz, 30 pF load at 66 MHz.

3. Only applicable as a constraint for the Write Status Register command when SPRL = 1

Serial Clock (SCK) Frequency 70 MHz

SCK Frequency for Read Array (Low Frequency - 03h opcode) 33 MHz

SCK High Time 6.4 ns

SCK Low Time 6.4 ns

SCK Rise Time, Peak-to-Peak (Slew Rate) 0.1 V/ns

SCK Fall Time, Peak-to-Peak (Slew Rate) 0.1 V/ns

Chip Select High Time 50 ns

Chip Select Low Setup Time (relative to SCK) 5 ns

Chip Select Low Hold Time (relative to SCK) 5 ns

Chip Select High Setup Time (relative to SCK) 5 ns

Chip Select High Hold Time (relative to SCK) 5 ns

Data In Setup Time 2 ns

Data In Hold Time 3 ns

Output Disable Time 6 ns

Output Valid Time 6ns

Output Hold Time 0 ns

HOLD Low Setup Time (relative to SCK) 5 ns

HOLD Low Hold Time (relative to SCK) 5 ns

HOLD High Setup Time (relative to SCK) 5 ns

HOLD High Hold Time (relative to SCK) 5 ns

HOLD Low to Output High-Z 6 ns

HOLD High to Output Low-Z 6 ns

Write Protect Setup Time 20 ns

Write Protect Hold Time 100 ns

Sector Protect Time (from Chip Select High) 20 ns

Sector Unprotect Time (from Chip Select High) 20 ns

Chip Select High to Deep Power-down 3 µs

Chip Select High to Standby Mode 3 µs

AT26DF081A

3600H–DFLASH–11/2012

AT26DF081A

12.5 Program and Erase Characteristics

Symbol Parameter Min Typ Max Units

(1)

BLKE

(2)

CHPE

(2)

WRSR

Notes: 1. Maximum values indicate worst-case performance after 100,000 erase/program cycles.

12.6 Power-up Conditions

Parameter Min Max Units

Minimum V

Power-up Device Delay Before Program or Erase Allowed 10 ms

Page Program Time (256 Bytes) 1.2 5 ms

Byte Program Time 7 µs

4 Kbytes 50 200

Block Erase Time

64 Kbytes 400 950

Chip Erase Time 6 14 sec

Write Status Register Time 200 ns

2. Not 100% tested (value guaranteed by design and characterization).

to Chip Select Low Time 50 µs

ms32 Kbytes 250 600

Power-on Reset Voltage 1.5 2.5 V

12.7 Input Test Waveforms and Measurement Levels

DRIVING

LEVELS

tR,tF< 2 ns (10% to 90%)

2.4V

0.45V

1.5V

AC MEASUREMENT LEVEL

12.8 Output Test Load

DEVICE UNDER

TEST

30 pF

3600H–DFLASH–11/2012

13. Waveforms

Figure 13-1. Serial Input Timing

CSLS

SCK

SCKH

SCKL

CSLH

CSHS

CSH

CSHH

HIGH-IMPEDANCE

MSB

Figure 13-2. Serial Output Timing

SCK

Figure 13-3.

HOLD Timing – Serial Input

MSBLSB

SCKH

SCKL

DIS

SCK

HOLD

HIGH-IMPEDANCE

AT26DF081A

HHH

HLS

HLH

HHS

3600H–DFLASH–11/2012

Figure 13-4. HOLD Timing – Serial Output

SCK

HHH

HOLD

HLS

HLH

HHS

AT26DF081A

HLQZ

HHQX

Figure 13-5. WP Timing for Write Status Register Command When SPRL = 1

WPS

WPH

SCK

WRITE STATUS REGISTER

HIGH-IMPEDANCE

000

MSB OF

OPCODE

LSB OF

WRITE STATUS REGISTER

DATA BYTE

MSBX

MSB OF

NEXT OPCODE

3600H–DFLASH–11/2012

14. Ordering Information

14.1 Green Package Options (Pb/Halide-free/RoHS Compliant)

(MHz) Ordering Code Package Operation Range

SCK

AT26DF081A-SSU 8S1

AT26DF081A-SU 8S2

(-40Cto85C)

Industrial

Package Type

8S1 8-lead, 0.150” Wide, Plastic Gull Wing Small Outline Package (JEDEC SOIC)

8S2 8-lead, 0.209” Wide, Plastic Gull Wing Small Outline Package (EIAJ SOIC)

AT26DF081A

3600H–DFLASH–11/2012

15. Packaging Information

15.1 8S1 – JEDEC SOIC

AT26DF081A

TOP VIEW

SIDE VIEW

Notes: This drawing is for general information only. Refer to JEDEC Drawing MS-012, Variation AA for proper dimensions, tolerances, datums, etc.

END VIEW

COMMON DIMENSIONS

(Unit of Measure = mm)

SYMBOL

A 1.35 – 1.75

A1 0.10 – 0.25

b 0.31 – 0.51

C 0.17 – 0.25

D 4.80 – 5.05

E1 3.81 – 3.99

E 5.79 – 6.20

e 1.27 BSC

L 0.40 – 1.27

ØØ 0° – 8°

MIN

NOM

MAX

NOTE

Package Drawing Contact:

contact@adestotech.com

3600H–DFLASH–11/2012

8S1, 8-lead (0.150” Wide Body), Plastic Gull Wing Small Outline (JEDEC SOIC)

SWB

6/22/11

DRAWING NO. REV. TITLE GPC

8S1 G

15.2 8S2 – EIAJ SOIC

TOP VIEW

END VIEW

SIDE VIEW

TOP VIEW

SIDE VIEW

Notes: 1. This drawing is for general information only; refer to EIAJ Drawing EDR-7320 for additional information.

2. Mismatch of the upper and lower dies and resin burrs aren't included.

3. Determines the true geometric position.

4. Values b,C apply to plated terminal. The standard thickness of the plating layer shall measure between 0.007 to .021 mm.

TITLE

Package Drawing Contact:

contact@adestotech.com

8S2, 8-lead, 0.208” Body, Plastic Small Outline Package (EIAJ)

END VIEW

SYMBOL

A 1.70 2.16

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 2

E 7.70 8.26

L 0.51 0.85

q 0° 8°

e 1.27 BSC 3

COMMON DIMENSIONS

(Unit of Measure = mm)

MIN

NOM

MAX

DRAWING NO. GPC

8S2 STN F

NOTE

4/15/08

REV.

AT26DF081A

3600H–DFLASH–11/2012

AT26DF081A

16. Revision History

Revision Level – Release Date History

A – November 2005 Initial Release

Added Global Protect and Global Unprotect Feature

- Made various minor text changes throughout document

B – March 2006

C – April 2006 Changed Note 5 of 8S2 package drawing to generalize terminal plating comment

D – May 2006

E – January 2007

- Added Global Protect/Unprotect section to document

- Changed Write Status Register section

Removed EPE bit from Status Register

Removed “Preliminary” designation. Changed page and byte program specifications in Section 12.5

- Increased typical page program time from 1.5 ms to 3.0 ms

- Increased maximum page program time from 3.0 ms to 5.0 ms

- Increased typical byte program time from 6 µs to 12 µs

Added footnote (1) to t

Added EPE bit description to the Read Status Register section. Reduced typical read currents in Section 12.3. Improved program and erase times in Section 12.5.

- Reduced typical page program time from 3.0 ms to 1.2 ms

- Reduced typical byte program time from 12 µs to 7 µs

- Reduced 32KB typical block erase time from 350 ms to 250 ms

- Reduced 64KB typical block erase time from 700 ms to 400 ms

- Reduced typical Chip Erase time from 10 sec to 6 sec

parameter in Section 12.5

CHPE

F – March 2007 Corrected 8S1 package drawing heading from EIAJ SOIC to JEDEC SOIC.

Updated to new template.

G – June 2009

H – November 2012 Update to Adesto

Corrected errors in datasheet missed when “Preliminary” designation was removed.

- Changed Deep Power-Down Current typical value from 10 µa to 25 µa

- Changed Deep Power-Down Current maximum value from 15 µa to 35 µa

3600H–DFLASH–11/2012

Corporate Office

California | USA Adesto Headquarters 1250 Borregas Avenue Sunnyvale, CA 94089 Phone: (+1) 408.400.0578 Email: contact@adestotech.com

Adesto®, the Adesto logo, CBRAM®, and DataFlash® are registered trademarks or trademarks of Adesto Technologies. All other marks are the property of their respective owners.

Disclaimer: Adesto Technologies Corporation makes no warranty for the use of its products, other than those expressly contained in the Company's standard warranty which is detailed in Adesto's Terms and Conditions located on the Company's web site. The Company assumes no responsibility for any errors which may appear in this document, reserves the right to change devices or specifications detailed herein at any time without notice, and does not make any commitment to update the information contained herein. No licenses to patents or other intellectual property of Adesto are granted by the Company in connection with the sale of Adesto products, expressly or by implication. Adesto's products are not authorized for use as critical components in life support devices or systems.

Rainbow Electronics AT26DF081A User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Features

1. Description

2. Pin Descriptions and Pinouts

3. Block Diagram

4. Memory Array

5. Device Operation

6. Commands and Addressing

7. Read Commands

7.1 Read Array

8. Program and Erase Commands

8.1 Byte/Page Program

8.2 Sequential Program Mode

8.3 Block Erase

8.4 Chip Erase

9. Protection Commands and Features

9.1 Write Enable

9.2 Write Disable

9.3 Protect Sector

9.4 Unprotect Sector

9.5 Global Protect/Unprotect

9.6 Read Sector Protection Registers

9.7 Protected States and the Write Protect (WP) Pin

10. Status Register Commands

10.1 Read Status Register

10.1.1 SPRL Bit

10.1.2 SPM Bit

10.1.3 EPE Bit

10.1.4 WPP Bit

10.1.5 SWP Bits

10.1.6 WEL Bit

10.1.7 RDY/BSY Bit

10.2 Write Status Register

11. Other Commands and Functions

11.1 Read Manufacturer and Device ID

11.2 Deep Power-down

11.3 Resume from Deep Power-down

11.4 Hold

12. Electrical Specifications

12.1 Absolute Maximum Ratings*

12.2 DC and AC Operating Range

12.3 DC Characteristics

12.4 AC Characteristics

12.5 Program and Erase Characteristics

12.6 Power-up Conditions

12.7 Input Test Waveforms and Measurement Levels

12.8 Output Test Load

13. Waveforms

14. Ordering Information

14.1 Green Package Options (Pb/Halide-free/RoHS Compliant)

15. Packaging Information

15.1 8S1 – JEDEC SOIC

15.2 8S2 – EIAJ SOIC

16. Revision History