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
– 40 mA Active Current
– 200 µA 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
Industrial Temperature Ranges
Green (Pb/Halide-free) Packaging Option Only
•
•
•
•
•
1-megabit
(128K x 8)
Paged Parallel
EEPROM
AT28C010
•
•
•
•
•
1. Description
The AT28C010 is a high-performance electrically-erasable and programmable read-
only memory. Its 1 megabit of memory is organized as 131,072 words by 8 bits. Man-
ufactured with Atmel’s advanced nonvolatile CMOS technology, the device offers
access times to 120 ns with power dissipation of just 220 mW. When the device is
deselected, the CMOS standby current is less than 200 µA.
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
writing 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
operations. Following the initiation of a write cycle, the device will automatically write
the latched data using an internal control 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 AT28C010 has additional features to ensure high quality and manufacturabil-
ity. The device utilizes internal error correction for extended endurance and improved
data retention characteristics. An optional software data protection mechanism is
available to guard against inadvertent writes. The device also includes an extra
128 bytes of EEPROM for device identification or tracking.
0353I–PEEPR–08/09
AT28C010
2. Pin Configurations
Pin Name
A0 - A16
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
A7
A6
A5
A4
A3
A2
A1
A0
I/O0
5
6
7
8
9
10
11
12
13
4
3
2
1
32
31
30
2.2
32-lead PLCC Top View
A12
A15
A16
DC
VCC
WE
NC
Note:
PLCC package pin 1 is Don’t Connect.
2.1
32-lead TSOP Top View
A11
A9
A8
A13
A14
NC
WE
VCC
NC
A16
A15
A12
A7
A6
A5
A4
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
OE
A10
CE
I/O7
I/O6
I/O5
I/O4
I/O3
GND
I/O2
I/O1
I/O0
A0
A1
A2
A3
I/O1
I/O2
GND
I/O3
I/O4
I/O5
I/O6
14
15
16
17
18
19
20
29
28
27
26
25
24
23
22
21
A14
A13
A8
A9
A11
OE
A10
CE
I/O7
2
0353I–PEEPR–08/09
AT28C010
3. Block Diagram
4. Device Operation
4.1
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 contention in their system.
4.2
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 automati-
cally time itself to completion. Once a programming operation has been initiated and for the
duration of t
WC
, a read operation will effectively be a polling operation.
4.3
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 additional
bytes. Each successive byte must be written within 150 µs (t
BLC
) of the previous byte. If the t
BLC
limit is exceeded the AT28C010 will cease accepting data and commence the internal program-
ming 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 operation, 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; unnecessary cycling of other bytes within the page does
not occur.
4.4
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/O
7
. 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.
3
0353I–PEEPR–08/09
4.5
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 tog-
gling and valid data will be read. Reading the toggle bit may begin at any time during the write
cycle.
4.6
Data Protection
If precautions are not taken, inadvertent writes may occur during transitions of the host system
power supply. Atmel
®
has incorporated both hardware and software features that will protect the
memory against inadvertent writes.
4.6.1
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;
and (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 Algo-
rithm). 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 command sequence is issued. Power transi-
tions 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 polling operations.
4.6.2
4.7
Device Identification
An extra 128 bytes of EEPROM memory are available to the user for device identification. By
raising A9 to 12V
±
0.5V and using address locations 1FF80H to 1FFFFH the bytes may be writ-
ten to or read from in the same manner as the regular memory array.
4.8
Optional Chip Erase Mode
The entire device can be erased using a 6-byte software code. Please see Software Chip Erase
application note for details.
4
AT28C010
0353I–PEEPR–08/09
AT28C010
5. DC and AC Operating Range
AT28C010-12
Operating Temperature (Case)
V
CC
Power Supply
Ind.
-40°C - 85°C
5V
±
10%
AT28C010-15
-40°C - 85°C
5V
±
10%
6. Operating Modes
Mode
Read
Write
(2)
Standby/Write Inhibit
Write Inhibit
Write Inhibit
Output Disable
Notes:
1. X can be V
IL
or V
IH
.
2. Refer to AC Programming Waveforms.
CE
V
IL
V
IL
V
IH
X
X
X
OE
V
IL
V
IH
X
(1)
X
V
IL
V
IH
WE
V
IH
V
IL
X
V
IH
X
X
High Z
I/O
D
OUT
D
IN
High Z
7. Absolute Maximum Ratings*
Temperature Under Bias................................ -55°C to +125°C
Storage Temperature ..................................... -65°C to +150°C
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
*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
8. DC Characteristics
Symbol
I
LI
I
LO
I
SB1
I
SB2
I
CC
V
IL
V
IH
V
OL
V
OH1
V
OH2
Parameter
Input Load Current
Output Leakage Current
V
CC
Standby Current CMOS
V
CC
Standby Current TTL
V
CC
Active Current
Input Low Voltage
Input High Voltage
Output Low Voltage
Output High Voltage
Output High Voltage CMOS
I
OL
= 2.1 mA
I
OH
= -400 µA
I
OH
= -100 µA; V
CC
= 4.5V
2.4
4.2
2.0
0.45
Condition
V
IN
= 0V to V
CC
+ 1V
V
I/O
= 0V to V
CC
CE = V
CC
- 0.3V to V
CC
+ 1V
CE = 2.0V to V
CC
+ 1V
f = 5 MHz; I
OUT
= 0 mA
Min
Max
10
10
200
3
40
0.8
Units
μA
μA
μA
mA
mA
V
V
V
V
V
5
0353I–PEEPR–08/09
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