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