AT45DB021D-MU datasheet(27/52 Pages) ATMEL

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3638B–DFLASH–02/07

AT45DB021D [Preliminary]

14.2

Operation Mode Summary

The commands described previously can be grouped into four different categories to better

describe which commands can be executed at what times.

Group A commands consist of:

Main Memory Page Read

Continuous Array Read

Read Sector Protection Register

Read Sector Lockdown Register

Read Security Register

Group B commands consist of:

Page Erase

Block Erase

Sector Erase

Chip Erase

Main Memory Page to Buffer Transfer

Main Memory Page to Buffer Compare

Buffer to Main Memory Page Program with Built-in Erase

Buffer to Main Memory Page Program without Built-in Erase

Main Memory Page Program through Buffer

10. Auto Page Rewrite

Group C commands consist of:

Buffer Read

Buffer Write

Status Register Read

Manufacturer and Device ID Read

Group D commands consist of:

Erase Sector Protection Register

Program Sector Protection Register

Sector Lockdown

Program Security Register

If a Group A command is in progress (not fully completed), then another command in Group A,

B, C, or D should not be started. However, during the internally self-timed portion of Group B

commands 1 through 4, any command in Group C can be executed. During the internally self-

timed portion of Group B commands 5 through 10, only Group C commands 3 and 4 can be exe-

cuted. Finally, during the internally self-timed portion of a Group D command, only the Status

AT45DB021D-MU Datasheet(PDF) 27 Page - ATMEL Corporation