AT45DB021D(AT45DB021D).pdf

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Features

1. Description

2. Pin Configurations and Pinouts

3. Block Diagram

4. Memory Array

5. Device Operation

6. Read Commands

6.1 Continuous Array Read (Legacy Command - E8H): Up to 66 MHz

6.2 Continuous Array Read (High Frequency Mode - 0BH): Up to 66 MHz

6.3 Continuous Array Read (Low Frequency Mode: 03H): Up to 33 MHz

6.4 Main Memory Page Read

6.5 Buffer Read

7. Program and Erase Commands

7.1 Buffer Write

7.2 Buffer to Main Memory Page Program with Built-in Erase

7.3 Buffer to Main Memory Page Program without Built-in Erase

7.4 Page Erase

7.5 Block Erase

7.6 Sector Erase

7.7 Chip Erase

7.8 Main Memory Page Program Through Buffer

8. Sector Protection

8.1 Software Sector Protection

8.1.1 Enable Sector Protection Command

8.1.2 Disable Sector Protection Command

8.1.3 Various Aspects About Software Controlled Protection

9. Hardware Controlled Protection

9.1 Sector Protection Register

9.1.1 Erase Sector Protection Register Command

9.1.2 Program Sector Protection Register Command

9.1.3 Read Sector Protection Register Command

9.1.4 Various Aspects About the Sector Protection Register

10. Security Features

10.1 Sector Lockdown

10.1.1 Sector Lockdown Register

10.1.2 Reading the Sector Lockdown Register

10.2 Security Register

10.2.1 Programming the Security Register

10.2.2 Reading the Security Register

11. Additional Commands

11.1 Main Memory Page to Buffer Transfer

11.2 Main Memory Page to Buffer Compare

11.3 Auto Page Rewrite

11.4 Status Register Read

12. Deep Power-down

12.1 Resume from Deep Power-down

13. “Power of 2” Binary Page Size Option

13.1 Programming the Configuration Register

14. Manufacturer and Device ID Read

14.1 Manufacturer and Device ID Information

14.1.1 Byte 1 - Manufacturer ID

14.1.2 Byte 2 - Device ID (Part 1)

14.1.3 Byte 3 - Device ID (Part 2)

14.1.4 Byte 4 - Extended Device Information String Length

14.2 Operation Mode Summary

15. Command Tables

16. Power-on/Reset State

16.1 Initial Power-up/Reset Timing Restrictions

17. System Considerations

18. Electrical Specifications

19. Input Test Waveforms and Measurement Levels

20. Output Test Load

21. AC Waveforms

21.1 Waveform 1 - SPI Mode 0 Compatible (for Frequencies up to 66 MHz)

21.2 Waveform 2 - SPI Mode 3 Compatible (for Frequencies up to 66 MHz)

21.3 Waveform 3 - RapidS Mode 0 (FMAX = 66 MHz)

21.4 Waveform 4 - RapidS Mode 3 (FMAX = 66 MHz)

21.5 Utilizing the RapidS Function

21.6 Reset Timing

21.7 Command Sequence for Read/Write Operations for Page Size 256 Bytes (Except Status Register Read, Manufacturer and Device ID Read)

21.8 Command Sequence for Read/Write Operations for Page Size 264 Bytes (Except Status Register Read, Manufacturer and Device ID Read)

22. Write Operations

22.1 Buffer Write

22.2 Buffer to Main Memory Page Program (Data from Buffer Programmed into Flash Page)

23. Read Operations

23.1 Main Memory Page Read

23.2 Main Memory Page to Buffer Transfer (Data from Flash Page Read into Buffer)

23.3 Buffer Read

24. Detailed Bit-level Read Waveform - RapidS Serial Interface Mode 0/Mode 3

24.1 Continuous Array Read (Legacy Opcode E8H)

24.2 Continuous Array Read (Opcode 0BH)

24.3 Continuous Array Read (Low Frequency: Opcode 03H)

24.4 Main Memory Page Read (Opcode: D2H)

24.5 Buffer Read (Opcode D4H)

24.6 Buffer Read (Low Frequency: Opcode D1H)

24.7 Read Sector Protection Register (Opcode 32H)

24.8 Read Sector Lockdown Register (Opcode 35H)

24.9 Read Security Register (Opcode 77H)

24.10 Status Register Read (Opcode D7H)

24.11 Manufacturer and Device Read (Opcode 9FH)

25. Auto Page Rewrite Flowchart

26. Ordering Information

26.1 Ordering Code Detail

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

27. Packaging Information

27.1 8MA1 - UDFN

27.2 8S1 - JEDEC SOIC

27.3 8S2 - EIAJ SOIC

28. Revision History

Features • Single 2.7V to 3.6V Supply RapidS® Serial Interface: 66 MHz Maximum Clock Frequency – SPI Compatible Modes 0 and 3 User Configurable Page Size – 256 Bytes per Page – 264 Bytes per Page – Page Size Can Be Factory Pre-configured for 256 Bytes Page Program Operation – Intelligent Programming Operation – 1,024 Pages (256/264 Bytes/Page) Main Memory Flexible Erase Options – Page Erase (256 Bytes) – Block Erase (2 Kbytes) – Sector Erase (32 Kbytes) – Chip Erase (2 Mbits) One SRAM Data Buffer (256/264 Bytes) Continuous Read Capability through Entire Array – Ideal for Code Shadowing Applications Low-power Dissipation – 7 mA Active Read Current Typical – 25 µA Standby Current Typical – 5 µA Deep Power-down Typical Hardware and Software Data Protection Features – Individual Sector Sector Lockdown for Secure Code and Data Storage – Individual Sector Security: 128-byte Security Register – 64-byte User Programmable Space – Unique 64-byte Device Identifier JEDEC Standard Manufacturer and Device ID Read 100,000 Program/Erase Cycles Per Page Minimum Data Retention – 20 Years Industrial Temperature Range Green (Pb/Halide-free/RoHS Compliant) Packaging Options 2-megabit 2.7-volt Minimum DataFlash® AT45DB021D 1. Description The AT45DB021D is a 2.7V, serial-interface Flash memory ideally suited for a wide variety of digital voice-, image-, program code- and data-storage applications. The AT45DB021D supports RapidS serial interface for applications requiring very high speed operations. RapidS serial interface is SPI compatible for frequencies up to 66 MHz. Its 2,162,688 bits of memory are organized as 1,024 pages of 256 bytes or 264 bytes each. In addition to the main memory, the AT45DB021D also contains one SRAM buffer of 256/264 bytes. EEPROM emulation (bit or byte alterability) is easily handled with a self-contained three step read-modify-write operation. Unlike conven- tional Flash memories that are accessed randomly with multiple address lines and a parallel interface, the 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. 3638F–DFLASH–4/08

The device is optimized for use in many commercial and industrial applications where high-den- sity, low-pin count, low-voltage and low-power are essential. To allow for simple in-system reprogrammability, the AT45DB021D does not require high input voltages for programming. The device operates from a single power supply, 2.7V to 3.6V, for both the program and read operations. The AT45DB021D 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 Table 2-1. Pin Configurations Symbol Name and Function CS SCK SI SO WP RESET Chip Select: Asserting the CS pin selects the device. When the CS pin is deasserted, the device will be deselected and normally be placed in the standby mode (not Deep Power-Down mode), and the output pin (SO) will be in a high-impedance state. When the device is deselected, data will not be accepted on the input pin (SI). A high-to-low transition on the CS pin is required to start an operation, and a low-to-high transition is required to end an operation. When ending an internally self-timed operation such as a program or erase cycle, the device will not enter the standby mode until the completion of the operation. Serial Clock: This pin is used to provide a clock to the device and is used to control the flow of data to and from the device. Command, address, and input data present on the SI pin is always latched on the rising edge of SCK, while output data on the SO pin is always clocked out on the falling edge of SCK. Serial Input: The SI pin is used to shift data into the device. The SI pin is used for all data input including command and address sequences. Data on the SI pin is always latched on the rising edge of SCK. 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 WP pin is asserted, all sectors specified for protection by the Sector Protection Register will be protected against program and erase operations regardless of whether the Enable Sector Protection command has been issued or not. The WP pin functions independently of the software controlled protection method. After the WP pin goes low, the content of the Sector Protection Register cannot be modified. If a program or erase command is issued to the device while the WP pin is asserted, the device will simply ignore the command and perform no operation. The device will return to the idle state once the CS pin has been deasserted. The Enable Sector Protection command and Sector Lockdown command, however, will be recognized by the device when the WP pin is asserted. The WP pin is internally pulled-high and may be left floating if hardware controlled protection will not be used. However, it is recommended that the WP pin also be externally connected to VCC whenever possible. Reset: A low state on the reset pin (RESET) will terminate the operation in progress and reset the internal state machine to an idle state. The device will remain in the reset condition as long as a low level is present on the RESET pin. Normal operation can resume once the RESET pin is brought back to a high level. The device incorporates an internal power-on reset circuit, so there are no restrictions on the RESET pin during power-on sequences. If this pin and feature are not utilized it is recommended that the RESET pin be driven high externally. VCC GND Device Power Supply: The VCC pin is used to supply the source voltage to the device. Operations at invalid VCC voltages may produce spurious results and should not be attempted. Ground: The ground reference for the power supply. GND should be connected to the system ground. 2 AT45DB021D Asserted State Type Low Input – – – Input Input Output Low Input Low Input – – Power Ground 3638F–DFLASH–4/08

AT45DB021D Figure 2-1. SOIC Top View Figure 2-2. UDFN Top View(1) SI SCK RESET CS 1 2 3 4 8 7 6 5 SO GND VCC WP SI SCK RESET CS 1 2 3 4 8 7 6 5 SO GND VCC WP Note: 1. The metal pad on the bottom of the UDFN package is floating. This pad can be a “No Connect” or connected to GND. 3. Block Diagram WP FLASH MEMORY ARRAY PAGE (256/264 BYTES) BUFFER (256/264 BYTES) SCK CS RESET VCC GND I/O INTERFACE SI SO 3638F–DFLASH–4/08 3

4. Memory Array To provide optimal flexibility, the memory array of the AT45DB021D is divided into three levels of granularity comprising of sectors, blocks, and pages. The “Memory Architecture Diagram” illus- trates 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. Figure 4-1. Memory Architecture Diagram SECTOR ARCHITECTURE BLOCK ARCHITECTURE PAGE ARCHITECTURE SECTOR 0a = 8 Pages 2,048/2,112 bytes SECTOR 0b = 120 Pages 31,744/32,726 bytes SECTOR 1 = 128 Pages 32,768/33,792 bytes SECTOR 6 = 128 Pages 32,768/33,792 bytes SECTOR 7 = 128 Pages 32,768/33,792 bytes SECTOR 0a b 0 R O T C E S 1 R O T C E S BLOCK 0 BLOCK 1 BLOCK 2 BLOCK 14 BLOCK 15 BLOCK 16 BLOCK 17 BLOCK 30 BLOCK 31 BLOCK 32 BLOCK 33 8 Pages 0 K C O L B 1 K C O L B PAGE 0 PAGE 1 PAGE 6 PAGE 7 PAGE 8 PAGE 9 PAGE 14 PAGE 15 PAGE 16 PAGE 17 PAGE 18 BLOCK 126 BLOCK 127 Block = 1,024/1,056 bytes PAGE 1,022 PAGE 1,023 Page = 256/264 bytes 5. Device Operation The device operation is controlled by instructions from the host processor. The list of instructions and their associated opcodes are contained in Tables 15-1 through 15-7. A valid instruction starts with the falling edge of CS followed by the appropriate 8-bit opcode and the desired buffer or main memory address location. While the CS pin is low, toggling the SCK pin controls the loading of the opcode and the desired 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 the DataFlash standard page size (264 bytes) is referenced in the datasheet using the terminology BFA8 - BFA0 to denote the 9 address bits required to designate a byte address within a buffer. Main memory addressing is referenced using the terminology PA9 - PA0 and BA8 - BA0, where PA9 - PA0 denotes the 10 address bits required to designate a page address and BA8 - BA0 denotes the 9 address bits required to designate a byte address within the page. For the “Power of 2” binary page size (256 bytes), the Buffer addressing is referenced in the datasheet using the conventional terminology BFA7 - BFA0 to denote the 8 address bits required to designate a byte address within a buffer. Main memory addressing is referenced using the terminology A17 - A0, where A17 - A8 denotes the 10 address bits required to desig- nate a page address and A7 - A0 denotes the 8 address bits required to designate a byte address within a page. 4 AT45DB021D 3638F–DFLASH–4/08

AT45DB021D 6. Read Commands By specifying the appropriate opcode, data can be read from the main memory or from the SRAM data buffer. The DataFlash supports RapidS protocols for Mode 0 and Mode 3. Please refer to the “Detailed Bit-level Read Timing” diagrams in this datasheet for details on the clock cycle sequences for each mode. 6.1 Continuous Array Read (Legacy Command – E8H): Up to 66 MHz 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 DataFlash standard page size (264 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 4 don’t care bytes. The first 10 bits (PA9 - PA0) of the 19-bit address sequence specify which page of the main memory array to read, and the last 9 bits (BA8 - BA0) of the 19-bit address sequence specify the starting byte address within the page. To perform a continuous read from the binary page size (256 bytes), the opcode (E8H) must be clocked into the device followed by three address bytes and 4 don’t care bytes. The first 10 bits (A17 - A8) of the 18-bits sequence specify which page of the main memory array to read, and the last 8 bits (A7 - A0) of the 18-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 cross- ing 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 fCAR1 specification. The Continuous Array Read bypasses the data buffer and leaves the contents of the buffer unchanged. 6.2 Continuous Array Read (High Frequency Mode – 0BH): Up to 66 MHz 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 fCAR1. To perform a continuous read array with the page size set to 264 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 10 bits (PA9 - PA0) of the 19-bit address sequence specify which page of the main memory array to read, and the last 9 bits (BA8 - BA0) of the 19-bit address sequence spec- ify the starting byte address within the page. To perform a continuous read with the page size set to 256 bytes, the opcode, 0BH, must be clocked into the device followed by three address bytes (A17 - 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. 3638F–DFLASH–4/08 5

The CS pin must remain low during the loading of the opcode, the address bytes, and the read- ing 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 con- tinue 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 fCAR1 specification. The Continuous Array Read bypasses the data buffer and leaves the contents of the buffer unchanged. 6.3 Continuous Array Read (Low Frequency Mode: 03H): Up to 33 MHz 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 fCAR2. To perform a continuous read array with the page size set to 264 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 10 bits (PA9 - PA0) of the 19-bit address sequence specify which page of the main memory array to read, and the last 9 bits (BA8 - BA0) of the 19-bit address sequence specify the starting byte address within the page. To perform a contin- uous read with the page size set to 256 bytes, the opcode, 03H, must be clocked into the device followed by three address bytes (A17 - 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 read- ing 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 con- tinue 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 the data buffer and leaves the contents of the buffer unchanged. 6.4 Main Memory Page Read A main memory page read allows the user to read data directly from any one of the 2,048 pages in the main memory, bypassing the data buffer and leaving the contents of the buffer unchanged. To start a page read from the DataFlash standard page size (264 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 4 don’t care bytes. The first 10 bits (PA9 - PA0) of the 19-bit address sequence specify the page in main memory to be read, and the last 9 bits (BA8 - BA0) of the 19-bit address sequence specify the starting byte address within that page. To start a page read from the binary page size (256 bytes), the opcode D2H must be clocked into the device followed by three address bytes and 4 don’t care bytes. The first 10 bits (A17 - A8) of the 18-bit sequence specify which page of the main memory array to read, and the last 8 bits (A7 - A0) of the 18-bit 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 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 6 AT45DB021D 3638F–DFLASH–4/08

6.5 Buffer Read AT45DB021D 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 fSCK specification. The Main Memory Page Read bypasses the data buffer and leaves the contents of the buffer unchanged. The SRAM data buffer can be accessed independently from the main memory array, and utiliz- ing the Buffer Read Command allows data to be sequentially read directly from the buffer. Two opcodes, D4H or D1H, 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 opcode can be used at any SCK frequency up to the maximum specified by fCAR1. The D1H opcode can be used for lower frequency read operations up to the maximum specified by fCAR2. To perform a buffer read from the DataFlash standard buffer (264 bytes), the opcode must be clocked into the device followed by three address bytes comprised of 15 don’t care bits and 9 buffer address bits (BFA8 - BFA0). To perform a buffer read from the binary buffer (256 bytes), the opcode must be clocked into the device followed by three address bytes comprised of 16 don’t care bits and 8 buffer address bits (BFA7 - 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). 7. Program and Erase Commands 7.1 Buffer Write Data can be clocked in from the input pin (SI) into the buffer. To load data into the DataFlash standard buffer (264 bytes), a 1-byte opcode, 84H, must be clocked into the device followed by three address bytes comprised of 15 don’t care bits and 9 buffer address bits (BFA8 - BFA0). The 9 buffer address bits specify the first byte in the buffer to be written. To load data into the binary buffers (256 bytes each), a 1-byte opcode, 84H, must be clocked into the device followed by three address bytes comprised of 16 don’t care bits and 8 buffer address bits (BFA7 - BFA0). The 8 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-to-high transition is detected on the CS pin. 7.2 Buffer to Main Memory Page Program with Built-in Erase Data written into the buffer can be programmed into the main memory. A 1-byte opcode, 83H, must be clocked into the device. For the DataFlash standard page size (264 bytes), the opcode must be followed by three address bytes consist of 5 don’t care bits, 10 page address bits (PA9 - PA0) that specify the page in the main memory to be written and 9 don’t care bits. To per- form a buffer to main memory page program with built-in erase for the binary page size (256 bytes), the opcode 83H must be clocked into the device followed by three address bytes consist- ing of 6 don’t care bits, 10 page address bits (A17 - A8) that specify the page in the main memory to be written and 8 don’t care bits. When a low-to-high transition occurs on the CS pin, 3638F–DFLASH–4/08 7

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 will indicate that the part is busy. 7.3 Buffer to Main Memory Page Program without Built-in Erase 7.4 Page Erase 7.5 Block Erase A previously-erased page within main memory can be programmed with the contents of the buffer. A 1-byte opcode, 88H, must be clocked into the device. For the DataFlash standard page size (264 bytes), the opcode must be followed by three address bytes consist of 5 don’t care bits, 10 page address bits (PA9 - PA0) that specify the page in the main memory to be written and 9 don’t care bits. To perform a buffer to main memory page program without built-in erase for the binary page size (256 bytes), the opcode 88H must be clocked into the device followed by three address bytes consisting of 6 don’t care bits, 10 page address bits (A17 - A8) that spec- ify the page in the main memory to be written and 8 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 will indicate that the part is busy. 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 DataFlash standard page size (264 bytes), an opcode of 81H must be loaded into the device, followed by three address bytes comprised of 5 don’t care bits, 10 page address bits (PA9 - PA0) that specify the page in the main memory to be erased and 9 don’t care bits. To perform a page erase in the binary page size (256 bytes), the opcode 81H must be loaded into the device, followed by three address bytes consist of 6 don’t care bits, 10 page address bits (A17 - A8) that specify the page in the main memory to be erased and 8 don’t care bits. When a low-to-high transition occurs on the CS pin, the part will erase the selected page (the erased state is a logical 1). The erase operation is internally self-timed and should take place in a maxi- mum time of tPE. During this time, the status register will indicate that the part is busy. 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 DataFlash standard page size (264 bytes), an opcode of 50H must be loaded into the device, followed by three address bytes comprised of 5 don’t care bits, 7 page address bits (PA9 -PA3) and 12 don’t care bits. The 7 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 (256 bytes), the opcode 50H must be loaded into the device, followed by three address bytes consisting of 6 don’t care bits, 7 page address bits (A17 - A11) and 11 don’t care bits. The 9 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 CS pin, the part will erase the selected block of eight pages. The erase operation is internally self-timed and should take place in a maximum time of tBE. During this time, the status register will indicate that the part is busy. 8 AT45DB021D 3638F–DFLASH–4/08

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