1

Features

– Single Cycle Reprogram (Erase and Program)

– Internal Address and Data Latches for 64 Bytes

– Page (64 Byte) Program Time – 10 ms

– Chip Erase Time – 10 ms

– 50 mA Active Current

–300 µA CMOS Standby Current

± 10% Supply

Description

The AT29C256 is a five-volt-only in-system Flash programmable and erasable read

only memory (PEROM). Its 256K of memory is organized as 32,768 words by 8 bits.

Manufactured with Atmel’s advanced nonvolatile CMOS technology, the device offers

access times to 70 ns with power dissipation of just 275 mW. When the device is

deselected, the CMOS standby current is less than 300 µA. The device endurance is

such that any sector can typically be written to in excess of 10,000 times.

256K (32K x 8)

5-volt Only

Flash Memory

AT29C256

Rev. 0046P–FLASH–10/04

PLCC and LCC Top View

Note:

PLCC package pins 1 and 17 are

DON’T CONNECT.

Pin Configurations

Pin Name

Function

A0 - A14

Addresses

CE

Chip Enable

OE

Output Enable

WE

Write Enable

I/O0 - I/O7

Data Inputs/Outputs

NC

No Connect

DC

Don’t Connect

5

6

7

8

9

10

11

12

13

29

28

27

26

25

24

23

22

21

A6

A5

A4

A3

A2

A1

A0

NC

I/O0

A8

A9

A11

NC

OE

A10

CE

I/O7

I/O6

TSOP Top View

Type 1

22

23

24

25

26

27

28

1

2

3

4

5

6

7

21

20

19

18

17

16

15

14

13

12

11

10

9

8

OE

A11

A9

A8

A13

A14

VCC

WE

A12

A7

A6

A5

A4

A3

A10

CE

I/O7

I/O6

I/O5

I/O4

I/O3

GND

I/O2

I/O1

I/O0

A0

A1

A2