1

Features

– Single Cycle Reprogram (Erase and Program)

– 1024 Pages (264 Bytes/Page) Main Memory

while Reprogramming of Nonvolatile Memory

µµµµs Typical Page to Buffer Transfer Time

– 15 mA Active Read Current Typical

–15

µA CMOS Standby Current Typical

Description

The AT45D021 is a 5-volt only, serial interface Flash memory suitable for in-system

reprogramming. Its 2,162,688 bits of memory are organized as 1024 pages of 264-

bytes each. In addition to the main memory, the AT45D021 also contains two data

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

the main memory is being reprogrammed. Unlike conventional Flash memories 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

5-volt Only

Serial

DataFlash

®

AT45D021

Rev. 0869B–07/98

Pin Configurations

Pin Name

Function

CS

Chip Select

SCK

Serial Clock

SI

Serial Input

SO

Serial Output

WP

Harware Page Write

Protect Pin

RESET

Chip Reset

RDY/BUSY

Ready/Busy

PLCC

Note:

PLCC package pins 16 and 17

are DON’T CONNECT.

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

28

27

26

25

24

23

22

21

20

19

18

17

16

15

RDY/BUSY

RESET

WP

NC

NC

VCC

GND

NC

NC

NC

CS

SCK

SI

SO

NC

NC

NC

NC

NC

NC

NC

NC

NC

NC

NC

NC

NC

NC

PLCC

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

(continued)