1
Features
Fast Read Access Time – 70 ns
5-volt Only Reprogramming
Page Program Operation
– Single Cycle Reprogram (Erase and Program)
– Internal Address and Data Latches for 64 Bytes
Internal Program Control and Timer
Hardware and Software Data Protection
Fast Program Cycle Times
– Page (64 Byte) Program Time – 10 ms
– Chip Erase Time – 10 ms
DATA Polling for End of Program Detection
Low-power Dissipation
– 50 mA Active Current
– 300
μA CMOS Standby Current
Typical Endurance > 10,000 Cycles
Single 5V
±
10% Supply
CMOS and TTL Compatible Inputs and Outputs
Commercial and Industrial Temperature Ranges
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
4
3
2
1
3
3
3
1
1
1
1
1
1
2
I
I
G
D
I
I
I
A
A
W
D
V
A
A
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