1

Features

– Single Cycle Reprogram (Erase and Program)

– 1024 Pages (264 Bytes/Page) Main Memory

while Reprogramming of Non-Volatile Memory

µµµµs Typical Page to Buffer Transfer Time

– 4 mA Active Read Current Typical

–5

µµµµA CMOS Standby Current Typical

Description

The AT45DB021 is a 2.7-volt only, serial interface Flash memory suitable for in-sys-

tem reprogramming. Its 2,162,688 bits of memory are organized as 1024 pages of

264-bytes each. In addition to the main memory, the AT45DB021 also contains two

SRAM data buffers of 264-bytes each. The buffers allow receiving of data while a

page in the main memory is being reprogrammed. Unlike conventional Flash memo-

ries that are accessed randomly with multiple address lines and a parallel interface,

the DataFlash uses a serial interface to sequentially access its data. The simple serial

interface facilitates hardware layout, increases system reliability, minimizes switching

2-Megabit

2.7-volt Only

Serial

DataFlash

®

AT45DB021

Rev. 0868B–07/98

Pin Configurations

Pin Name

Function

CS

Chip Select

SCK

Serial Clock

SI

Serial Input

SO

Serial Output

WP

Hardware Page Write

Protect Pin

RESET

Chip Reset

RDY/BUSY

Ready/Busy

(continued)

PLCC

5

6

7

8

9

10

11

12

13

29

28

27

26

25

24

23

22

21

SCK

SI

SO

NC

NC

NC

NC

NC

NC

WP

RESET

RDY/BUSY

NC

NC

NC

NC

NC

NC

TSOP Top View

Type 1

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

32

31

30

29

28

27

26

25

24

23

22

21

20

19

18

17

RDY/BUSY

RESET

WP

NC

NC

NC

VCC

GND

NC

NC

NC

NC

CS

SCK

SI

SO

NC

NC

NC

NC

NC

NC

NC

NC

NC

NC

NC

NC

NC

NC

NC

NC

SOIC

1

2

3

4

5

6

7

8

9

10

11

12

13

14

28

27

26

25

24

23

22

21

20

19

18

17

16

15

GND

NC

NC

CS

SCK

SI

SO

NC

NC

NC

NC

NC

NC

NC

VCC

NC

NC

WP

RESET

RDY/BUSY

NC

NC

NC

NC

NC

NC

NC

NC

Note: PLCC package pins 16

and 17 are DON’T CONNECT.