1
Features
Fast Read Access Time - 120 ns
Automatic Page Write Operation
Internal Address and Data Latches for 128-Bytes
Internal Control Timer
Fast Write Cycle Time
Page Write Cycle Time - 10 ms Maximum
1 to 128-Byte Page Write Operation
Low Power Dissipation
80 mA Active Current
300
A CMOS Standby Current
Hardware and Software Data Protection
DATA Polling for End of Write Detection
High Reliability CMOS Technology
Endurance: 10
4
or 10
5
Cycles
Data Retention: 10 Years
Single 5V
10% Supply
CMOS and TTL Compatible Inputs and Outputs
JEDEC Approved Byte-Wide Pinout
Description
The AT28C010 is a high-performance Electrically Erasable and Programmable Read
Only Memory. Its one megabit of memory is organized as 131,072 words by 8 bits.
Manufactured with Atmel's advanced nonvolatile CMOS technology, the device offers
access times to 120 ns with power dissipation of just 440 mW. When the device is
deselected, the CMOS standby current is less than 300
A.
Rev. 0010C10/98
Pin Configuration
Pin Name
Function
A0 - A16
Addresses
CE
Chip Enable
OE
Output Enable
WE
Write Enable
I/O0 - I/O7
Data Inputs/Outputs
NC
No Connect
AT28C010 Mil
1-Megabit
(128K x 8)
Paged Parallel
EEPROMs
AT28C010
Military
CERDIP, FLATPACK
Top View
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
NC
A16
A15
A12
A7
A6
A5
A4
A3
A2
A1
A0
I/O0
I/O1
I/O2
GND
VCC
WE
NC
A14
A13
A8
A9
A11
OE
A10
CE
I/O7
I/O6
I/O5
I/O4
I/O3
PGA
Top View
44 LCC
Top View
7
8
9
10
11
12
13
14
15
16
17
39
38
37
36
35
34
33
32
31
30
29
A12
A7
A6
A5
NC
NC
NC
A4
A3
A2
A1
A13
A8
A9
A11
NC
NC
NC
NC
OE
A10
CE
6
5
4
3
2
1
44
43
42
41
40
18
19
20
21
22
23
24
25
26
27
28
A0
I/O0
I/O1
I/O2
VSS
NC
I/O3
I/O4
I/O5
I/O6
I/O7
A15
A16
NC
NC
NC
NC
VCC
WE
NC
NC
A14
32 LCC
Top View
5
6
7
8
9
10
11
12
13
29
28
27
26
25
24
23
22
21
A7
A6
A5
A4
A3
A2
A1
A0
I/O0
A14
A13
A8
A9
A11
OE
A10
CE
I/O7
4
3
2
1
32
31
30
14
15
16
17
18
19
20
I/O1
I/O2
GND
I/O3
I/O4
I/O5
I/O6
A12
A15
A16
NC
VCC
WE
NC
(continued)
AT28C010 Mil
2
The AT28C010 is accessed like a Static RAM for the read
or write cycle without the need for external components.
The device contains a 128-byte page register to allow writ-
ing of up to 128-bytes simultaneously. During a write cycle,
the address and 1 to 128-bytes of data are internally
latched, freeing the address and data bus for other opera-
tions. Following the initiation of a write cycle, the device will
automatically write the latched data using an internal con-
trol timer. The end of a write cycle can be detected by
DATA POLLING of I/O7. Once the end of a write cycle has
been detected a new access for a read or write can begin.
Atmel's 28C010 has additional features to ensure high
quality and manufacturability. The device utilizes internal
error correction for extended endurance and improved data
retention characteristics. An optional software data protec-
tion mechanism is available to guard against inadvertent
writes. The device also includes an extra 128-bytes of
EEPROM for device identification or tracking.
Block Diagram
Absolute Maximum Ratings*
Temperature Under Bias ................................ -55C to +125C
*NOTICE:
Stresses beyond those listed under "Absolute
Maximum Ratings" may cause permanent dam-
age to the device. This is a stress rating only and
functional operation of the device at these or any
other conditions beyond those indicated in the
operational sections of this specification is not
implied. Exposure to absolute maximum rating
conditions for extended periods may affect device
reliability.
Storage Temperature ..................................... -65C to +150C
All Input Voltages
(including NC Pins)
with Respect to Ground ...................................-0.6V to +6.25V
All Output Voltages
with Respect to Ground .............................-0.6V to V
CC
+ 0.6V
Voltage on OE and A9
with Respect to Ground ...................................-0.6V to +13.5V
AT28C010 Mil
3
Device Operation
READ: The AT28C010 is accessed like a Static RAM.
When CE and OE are low and WE is high, the data stored
at the memory location determined by the address pins is
asserted on the outputs. The outputs are put in the high
impedance state when either CE or OE is high. This dual-
line control gives designers flexibility in preventing bus con-
tention in their system.
BYTE WRITE: A low pulse on the WE or CE input with CE
or WE low (respectively) and OE high initiates a write cycle.
The address is latched on the falling edge of CE or WE,
whichever occurs last. The data is latched by the first rising
edge of CE or WE. Once a byte write has been started it
will automatically time itself to completion. Once a pro-
gramming operation has been initiated and for the duration
of t
WC
, a read operation will effectively be a polling opera-
tion.
PAGE WRITE: The page write operation of the AT28C010
allows 1 to 128-bytes of data to be written into the device
during a single internal programming period. A page write
operation is initiated in the same manner as a byte write;
the first byte written can then be followed by 1 to 127 addi-
tional bytes. Each successive byte must be written within
150
s (t
BL C
) of the previous byte. If the t
BLC
limit is
exceeded the AT28C010 will cease accepting data and
commence the internal programming operation. All bytes
during a page write operation must reside on the same
page as defined by the state of the A7 - A16 inputs. For
each WE high to low transition during the page write opera-
tion, A7 - A16 must be the same.
The A0 to A6 inputs are used to specify which bytes within
the page are to be written. The bytes may be loaded in any
order and may be altered within the same load period. Only
bytes which are specified for writing will be written; unnec-
essary cycling of other bytes within the page does not
occur.
DATA POLLING: The AT28C010 features DATA Polling to
indicate the end of a write cycle. During a byte or page
write cycle an attempted read of the last byte written will
result in the complement of the written data to be presented
on I/O7. Once the write cycle has been completed, true
data is valid on all outputs, and the next write cycle may
begin. DATA Polling may begin at anytime during the write
cycle.
TOGGLE BIT: In addition to DATA Polling the AT28C010
provides another method for determining the end of a write
cycle. During the write operation, successive attempts to
read data from the device will result in I/O6 toggling
between one and zero. Once the write has completed, I/O6
will stop toggling and valid data will be read. Reading the
toggle bit may begin at any time during the write cycle.
DATA PROTECTION: If precautions are not taken, inad-
vertent writes may occur during transitions of the host sys-
tem power supply. Atmel has incorporated both hardware
and software features that will protect the memory against
inadvertent writes.
HARDWARE PROTECTION: Hardware features protect
against inadvertent writes to the AT28C010 in the following
ways: (a) V
CC
sense - if V
CC
is below 3.8V (typical) the write
function is inhibited; (b) V
CC
power-on delay - once V
CC
has
reached 3.8V the device will automatically time out 5 ms
(typical) before allowing a write: (c) write inhibit - holding
any one of OE low, CE high or WE high inhibits write
cycles; (d) noise filter - pulses of less than 15 ns (typical)
on the WE or CE inputs will not initiate a write cycle.
SOFTWARE DATA PROTECTION: A software controlled
data protection feature has been implemented on the
AT28C010. When enabled, the software data protection
(SDP), will prevent inadvertent writes. The SDP feature
may be enabled or disabled by the user; the AT28C010 is
shipped from Atmel with SDP disabled.
SDP is enabled by the host system issuing a series of three
write commands; three specific bytes of data are written to
three specific addresses (refer to Software Data Protection
Algorithm). After writing the 3-byte command sequence
and after t
WC
the entire AT28C010 will be protected against
inadvertent write operations. It should be noted, that once
protected the host may still perform a byte or page write to
the AT28C010. This is done by preceding the data to be
written by the same 3-byte command sequence used to
enable SDP.
Once set, SDP will remain active unless the disable com-
mand sequence is issued. Power transitions do not disable
SDP and SDP will protect the AT28C010 during power-up
and power-down conditions. All command sequences must
conform to the page write timing specifications. The data in
the enable and disable command sequences is not written
to the device and the memory addresses used in the
sequence may be written with data in either a byte or page
write operation.
After setting SDP, any attempt to write to the device without
the 3-byte command sequence will start the internal write
timers. No data will be written to the device; however, for
the duration of t
WC
, read operations will effectively be poll-
ing operations.
D EVIC E ID EN TI FI CA TI ON : A n ex tra 1 2 8- by te s o f
EEPROM memory are available to the user for device iden-
tification. By raising A9 to 12V
0.5V and using address
locations 1FF80H to 1FFFFH the bytes may be written to or
read from in the same manner as the regular memory
array.
OPTIONAL CHIP ERASE MODE: The entire device can
be erased using a 6-byte software code. Please see Soft-
ware Chip Erase application note for details.
AT28C010 Mil
5
AC Read Waveforms
(1)(2)(3)(4)
Notes:
1. CE may be delayed up to t
ACC
- t
CE
after the address transition without impact on t
ACC
.
2. OE may be delayed up to t
CE
- t
OE
after the falling edge of CE without impact on t
CE
or by t
ACC
- t
OE
after an address change
without impact in t
ACC
.
3. t
DF
is specified from OE or CE wichever occurs first (CL = 5 pF).
4. This parameter is characterized and is not 100% tested.
Input Test Waveforms and
Measurement Level
Output Test Load
Note:
1. This parameter is 100% characterized and is not 100% tested.
AC Read Characteristics
Symbol
Parameter
AT28C010-12
AT28C010-15
AT28C010-20
AT28C010-25
Units
Min
Max
Min
Max
Min
Max
Min
Max
t
ACC
Address to Output Delay
120
150
200
250
ns
t
CE
(1)
CE to Output Delay
120
150
200
250
ns
t
OE
(2)
OE to Output Delay
0
50
0
55
0
55
0
55
ns
t
DF
(3, 4)
CE or OE to Output Float
0
50
0
55
0
55
0
55
ns
t
OH
Output Hold from OE, CE or
Address, whichever occurred first
0
0
0
0
ns
Pin Capacitance
f = 1 MHz, T = 25C
(1)
Symbol
Typ
Max
Units
Conditions
C
IN
4
10
pF
V
IN
= 0V
C
OUT
8
12
pF
V
OUT
= 0V
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