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
256K (32K x 8)
5-volt Only
Flash Memory
AT29C256
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.
Pin Configurations
Pin Name
A0 - A14
CE
OE
WE
I/O0 - I/O7
NC
DC
Function
Addresses
Chip Enable
Output Enable
Write Enable
Data Inputs/Outputs
No Connect
Don’t Connect
OE
A11
A9
A8
A13
A14
VCC
WE
A12
A7
A6
A5
A4
A3
22
23
24
25
26
27
28
1
2
3
4
5
6
7
TSOP Top View
Type 1
21
20
19
18
17
16
15
14
13
12
11
10
9
8
A10
CE
I/O7
I/O6
I/O5
I/O4
I/O3
GND
I/O2
I/O1
I/O0
A0
A1
A2
PLCC and LCC Top View
4
3
2
1
32
31
30
A7
A12
WE
DC
VCC
A14
A13
Note:
PLCC package pins 1 and 17 are
DON’T CONNECT.
I/O1
I/O2
GND
DC
I/O3
I/O4
I/O5
14
15
16
17
18
19
20
A6
A5
A4
A3
A2
A1
A0
NC
I/O0
5
6
7
8
9
10
11
12
13
29
28
27
26
25
24
23
22
21
A8
A9
A11
NC
OE
A10
CE
I/O7
I/O6
Rev. 0046P–FLASH–10/04
1
ATMEL [ ATMEL CORPORATION ]
