X28HC256
1
©Xicor, Inc. 1991, 1995 Patents Pending Characteristics subject to change without notice
3859-2.8 8/5/97 T1/C0/D0 EW
5 Volt, Byte Alterable E
2
PROM
FEATURES
• Access Time: 70ns
• Simple Byte and Page Write
—Single 5V Supply
—No External High Voltages or V
PP
Control
Circuits
—Self-Timed
—No Erase Before Write
—No Complex Programming Algorithms
—No Overerase Problem
• Low Power CMOS:
—Active: 60mA
—Standby: 500µA
• Software Data Protection
—Protects Data Against System Level
Inadvertent Writes
• High Speed Page Write Capability
• Highly Reliable Direct Write
™
Cell
—Endurance: 100,000 Write Cycles
—Data Retention: 100 Years
• Early End of Write Detection
—DATA Polling
—Toggle Bit Polling
DESCRIPTION
The X28HC256 is a second generation high perfor-
mance CMOS 32K x 8 E
2
PROM. It is fabricated with
Xicor’s proprietary, textured poly floating gate tech-
nology, providing a highly reliable 5 Volt only nonvolatile
memory.
The X28HC256 supports a 128-byte page write opera-
tion, effectively providing a 24µs/byte write cycle and
enabling the entire memory to be typically rewritten in
less than 0.8 seconds. The X28HC256 also features
DATA Polling and Toggle Bit Polling, two methods of
providing early end of write detection. The X28HC256
also supports the JEDEC standard Software Data Pro-
tection feature for protecting against inadvertent writes
during power-up and power-down.
Endurance for the X28HC256 is specified as a minimum
100,000 write cycles per byte and an inherent data
retention of 100 years.
256K X28HC256 32K x 8 Bit
PIN CONFIGURATION
LCC
PLCC
A
6
A
5
A
4
A
3
A
2
A
1
A
0
NC
I/O
0
A
8
A
9
A
11
NC
OE
A
10
CE
I/O
7
I/O
6
4 3 2 1 32 31 30
14 15 16 17 18 19 20
5
6
7
8
9
10
11
12
13
29
28
27
26
25
24
23
22
21
X28HC256
A
7
A
12
A
14
NC
V
CC
WE
A
13
I/O
1
I/O
2
V
SS
NC
I/O
3
I/O
4
I/O
5
PLASTIC DIP
CERDIP
FLAT PACK
SOIC
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
X28HC256
A
3
A
4
A
5
A
6
A
7
A
12
A
14
NC
V
CC
NC
WE
A
13
A
8
A
9
A
11
OE
32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
A
2
A
1
A
0
I/O
0
I/O
1
I/O
2
NC
V
SS
NC
I/O
3
I/O
4
I/O
5
I/O
6
I/O
7
CE
A
10
3859 ILL F22
TSOP
3859 FHD F03
A14
A
12
A
7
A
6
A
5
A
4
A
3
A
2
A
1
A
0
I/O
0
I/O
1
I/O
2
V
SS
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
V
CC
WE
A
13
A
8
A
9
A
11
OE
A
10
CE
I/O
7
I/O
6
I/O
5
I/0
4
I/O
3
X28HC256
3859 FHD F02