User guide
Table Of Contents
- Features
- 1. Description
- 2. Pin Configurations and Pinouts
- 3. Block Diagram
- 4. Memory Array
- 5. Device Operation
- 6. Read Commands
- 7. Program and Erase Commands
- 8. Sector Protection
- 9. Hardware Controlled Protection
- 10. Security Features
- 11. Additional Commands
- 12. Deep Power-down
- 13. “Power of 2” Binary Page Size Option
- 14. Manufacturer and Device ID Read
- 15. Command Tables
- 16. Power-on/Reset State
- 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 66MHz)
- 21.2 Waveform 2 – SPI Mode 3 Compatible (for Frequencies up to 66MHz)
- 21.3 Waveform 3 – RapidS Mode 0 (FMAX = 66MHz)
- 21.4 Waveform 4 – RapidS Mode 3 (FMAX = 66MHz)
- 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
- 23. Read Operations
- 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 or D6H)
- 24.6 Buffer Read (Low Frequency: Opcode D1H or D3H)
- 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
- 27. Packaging Information
- 28. Revision History
- 29. Errata
46
3596N–DFLASH–11/2012
AT45DB081D
Figure 25-2. Algorithm for Randomly Modifying Data
Notes: 1. To preserve data integrity, each page of an DataFlash sector must be updated/rewritten at least once within every 10,000
cumulative page erase and program operations.
2. A Page Address Pointer must be maintained to indicate which page is to be rewritten. The Auto Page Rewrite command
must use the address specified by the Page Address Pointer.
3. Other algorithms can be used to rewrite portions of the Flash array. Low-power applications may choose to wait until 10,000
cumulative page erase and program operations have accumulated before rewriting all pages of the sector. See application
note AN-4 (“Using Serial DataFlash”) for more details.
START
MAIN MEMORY PAGE
TO BUFFER TRANSFER
(53H, 55H)
INCREMENT PAGE
ADDRESS POINTER
(2)
AUTO PAGE REWRITE
(2)
(58H, 59H)
END
provide address of
page to modify
If planning to modify multiple
bytes currently stored within
a page of the Flash array
MAIN MEMORY PAGE PROGRAM
THROUGH BUFFER
(82H, 85H)
BUFFER WRITE
(84H, 87H)
BUFFER TO MAIN
MEMORY PAGE PROGRAM
(83H, 86H)