ATMEL AT28HC64B 64k 8k x 8 high speed cmos e2prom with page write and software data protection Datasheet

AT28HC64B
Features
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Fast Read Access Time - 55 ns
Automatic Page Write Operation
Internal Address and Data Latches for 64-Bytes
Fast Write Cycle Times
Page Write Cycle Time: 10 ms Maximum
1 to 64-Byte Page Write Operation
Low Power Dissipation
40 mA Active Current
100 µA CMOS Standby Current
Hardware and Software Data Protection
DATA Polling and Toggle Bit for End of Write Detection
High Reliability CMOS Technology
Endurance: 100,000 Cycles
Data Retention: 10 Years
Single 5V ± 10% Supply
CMOS and TTL Compatible Inputs and Outputs
JEDEC Approved Byte-Wide Pinout
Commercial and Industrial Temperature Ranges
Description
The AT28HC64B is a high-performance electrically erasable and programmable read
only memory (EEPROM). Its 64K of memory is organized as 8,192 words by 8 bits.
Manufactured with Atmel’s advanced nonvolatile CMOS technology, the device offers
access times to 55 ns with power dissipation of just 220 mW. When the device is
deselected, the CMOS standby current is less than 100 µA.
64K (8K x 8)
High Speed
CMOS
E2PROM with
Page Write and
Software Data
Protection
The AT28HC64B is accessed like a Static RAM for the read or write cycle without the
need for external components. The device contains a 64-byte page register to allow
(continued)
Pin Configurations
Pin Name
Function
A0 - A12
Addresses
CE
Chip Enable
OE
Output Enable
WE
Write Enable
I/O0 - I/O7
Data Inputs/Outputs
NC
No Connect
DC
Don’t Connect
PDIP, SOIC
Top View
TSOP
Top View
AT28HC64B
PLCC
Top View
Note: PLCC package pins 1 and
17 are DON’T CONNECT.
0274D
2-267
Description (Continued)
writing of up to 64-bytes simultaneously. During a write cycle, the addresses and 1 to 64-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 AT28HC64B has additional features to ensure
high quality and manufacturability. The device utilizes internal error correction for extended endurance and improved data retention. An optional software data protection mechanism is available to guard against inadvertent
writes. The device also includes an extra 64-bytes of
EEPROM for device identification or tracking.
Block Diagram
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 VCC + 0.6V
Voltage on OE and A9
with Respect to Ground ................... -0.6V to +13.5V
2-268
AT28HC64B
*NOTICE: Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage 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.
AT28HC64B
Device Operation
READ: The AT28HC64B 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 highimpedance state when either CE or OE is high. This dual
line control gives designers flexibility in preventing bus
contention in their systems.
read. Toggle bit reading may begin at any time during the
write cycle.
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 programming operation has been initiated and for the
duration of tWC, a read operation will effectively be a polling operation.
HARDWARE DATA PROTECTION: Hardware features
protect against inadvertent writes to the AT28HC64B in
the following ways: (a) VCC sense - if VCC is below 3.8V
(typical), the write function is inhibited; (b) VCC power-on
delay - once VCC 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.
PAGE WRITE: T h e p a g e w r i t e o p e r a t i o n o f t h e
AT28HC64B allows 1 to 64-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; after the first byte is written, it can then be followed by 1 to 63 additional bytes. Each successive byte
must be loaded within 150 µs (tBLC) of the previous byte.
If the tBLC limit is exceeded, the AT28HC64B 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 A6 to
A12 inputs. For each WE high to low transition during the
page write operation, A6 to A12 must be the same.
The A0 to A5 inputs 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.
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.
SOFTWARE DATA PROTECTION: A software-controlled data protection feature has been implemented on the
AT28HC64B. When enabled, the software data protection
(SDP), will prevent inadvertent writes. The SDP feature
may be enabled or disabled by the user; the AT28HC64B
is shipped from Atmel with SDP disabled.
SDP is enabled by the user issuing a series of three write
commands in which three specific bytes of data are written
to three specific addresses (refer to the Software Data
Protection Algorithm diagram in this data sheet). After writing the 3-byte command sequence and waiting tWC, the
entire AT28HC64B will be protected against inadvertent
writes. It should be noted that even after SDP is enabled,
the user may still perform a byte or page write to the
AT28HC64B. This is done by preceding the data to be
written by the same 3-byte command sequence used to
enable SDP.
DATA POLLING: The AT28HC64B 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 any time during the
write cycle.
Once set, SDP remains active unless the disable command sequence is issued. Power transitions do not disable SDP, and SDP protects the AT28HC64B 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 actually written into the device; their addresses may still be written with user data in either a byte
or page write operation.
TOGGLE BIT: I n a d d i t i o n t o DATA P o l l i n g , t he
AT28HC64B 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
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 tWC, read operations will effectively be
polling operations.
(continued)
2-269
Device Operation (Continued)
DEVICE IDENTIFICATION: A n e x t r a 6 4 - b y t e s o f
EEPROM memory are available to the user for device
identification. By raising A9 to 12V ± 0.5V and using ad-
dress locations 1FC0H to 1FFFH, the additional bytes
may be written to or read from in the same manner as the
regular memory array.
DC and AC Operating Range
Operating
Temperature (Case)
AT28HC64B-55
AT28HC64B-70
AT28HC64B-90
AT28HC64B-120
0°C - 70°C
0°C - 70°C
0°C - 70°C
0°C - 70°C
-40°C - 85°C
-40°C - 85°C
-40°C - 85°C
5V ± 10%
5V ± 10%
5V ± 10%
Com.
Ind.
5V ± 10%
VCC Power Supply
Operating Modes
Mode
CE
OE
WE
I/O
Read
VIL
VIL
VIH
DOUT
Write (2)
VIL
VIH
VIL
DIN
VIH
(1)
Standby/Write Inhibit
X
X
High Z
Write Inhibit
X
X
VIH
Write Inhibit
X
VIL
X
Output Disable
X
VIH
X
High Z
VIL
High Z
Chip Erase
VH
VIL
Notes: 1. X can be VIL or VIH.
2. Refer to the AC Write Waveforms diagrams
in this data sheet.
(3)
3. VH = 12.0V ± 0.5V.
DC Characteristics
Symbol
Parameter
Condition
Min
Max
Units
ILI
Input Load Current
VIN = 0V to VCC + 1V
10
µA
ILO
Output Leakage Current
VI/O = 0V to VCC
10
µA
ISB1
VCC Standby Current CMOS
CE = VCC - 0.3V to VCC + 1V
ISB2
VCC Standby Current TTL
CE = 2.0V to VCC + 1V
ICC
VCC Active Current
f = 5 MHz; IOUT = 0 mA
VIL
Input Low Voltage
VIH
Input High Voltage
VOL
Output Low Voltage
IOL = 2.1 mA
VOH
Output High Voltage
IOH = -400 µA
Note:
2-270
100
2
(1)
mA
mA
0.8
V
V
.40
2.4
µA
40
2.0
1. ISB1 and ISB2 for the 55 ns part is 40 mA maximum.
AT28HC64B
Com., Ind.
(1)
V
V
AT28HC64B
AC Read Characteristics
AT28HC64B-55 AT28HC64B-70 AT28HC64B-90 AT28HC64B-120
Symbol Parameter
Min
Max
Min
Max
Min
Max
Min
Max
Units
tACC
Address to Output Delay
55
70
90
120
ns
tCE (1)
CE to Output Delay
55
70
90
120
ns
tOE
(2)
OE to Output Delay
0
30
0
35
0
40
0
50
ns
tDF
(3, 4)
OE to Output Float
0
30
0
35
0
40
0
50
ns
Output Hold
0
tOH
0
0
0
ns
AC Read Waveforms (1, 2, 3, 4)
Notes: 1. CE may be delayed up to tACC - tCE after the address
transition without impact on tACC.
2. OE may be delayed up to tCE - tOE after the falling
edge of CE without impact on tCE or by tACC - tOE
after an address change without impact on tACC.
3. tDF is specified from OE or CE, whichever occurs first
(CL = 5 pF).
4. This parameter is characterized and is not 100% tested.
Input Test Waveforms and
Measurement Level
Output Test Load
tR, tF < 5ns
Pin Capacitance (f = 1 MHz, T = 25°C) (1)
Typ
Max
Units
CIN
4
6
pF
VIN = 0V
COUT
8
12
pF
VOUT = 0V
Note:
Conditions
1. This parameter is characterized and is not 100% tested.
2-271
AC Write Characteristics
Symbol
Parameter
tAS, tOES
Address, OE Set-up Time
0
ns
tAH
Address Hold Time
50
ns
tCS
Chip Select Set-up Time
0
ns
tCH
Chip Select Hold Time
0
ns
tWP
Write Pulse Width (WE or CE)
100
ns
tDS
Data Set-up Time
50
ns
tDH, tOEH
Data, OE Hold Time
0
ns
AC Write Waveforms
WE Controlled
CE Controlled
2-272
AT28HC64B
Min
Max
Units
AT28HC64B
Page Mode Characteristics
Symbol
Parameter
Min
Max
Units
tWC
Write Cycle Time
10
ms
tAS
Address Set-up Time
0
ns
tAH
Address Hold Time
50
ns
tDS
Data Set-up Time
50
ns
tDH
Data Hold Time
0
ns
tWP
Write Pulse Width
100
ns
tBLC
Byte Load Cycle Time
tWPH
Write Pulse Width High
150
50
µs
ns
Page Mode Write Waveforms (1, 2)
Notes: 1. A6 through A12 must specify the same page address during each high to low transition of WE (or CE).
2. OE must be high only when WE and CE are both low.
Chip Erase Waveforms
tS = tH = 5 µsec (min.)
tW = 10 msec (min.)
VH = 12.0V ± 0.5V
2-273
Software Data
Protection Enable Algorithm (1)
Software Data
Protection Disable Algorithm (1)
LOAD DATA AA
TO
ADDRESS 1555
LOAD DATA AA
TO
ADDRESS 1555
LOAD DATA 55
TO
ADDRESS 0AAA
LOAD DATA 55
TO
ADDRESS 0AAA
LOAD DATA A0
TO
ADDRESS 1555
LOAD DATA 80
TO
ADDRESS 1555
WRITES ENABLED (2)
LOAD DATA AA
TO
ADDRESS 1555
LOAD DATA XX
TO
ANY ADDRESS (4)
LOAD LAST BYTE
TO
LAST ADDRESS
ENTER DATA
PROTECT STATE
Notes for software program code:
1. Data Format: I/O7 - I/O0 (Hex);
Address Format: A12 - A0 (Hex).
2. Write Protect state will be activated at end of write even if no
other data is loaded.
3. Write Protect state will be deactivated at end of write period
even if no other data is loaded.
4. 1 to 64-bytes of data are loaded.
LOAD DATA 55
TO
ADDRESS 0AAA
LOAD DATA 20
TO
ADDRESS 1555
EXIT DATA
PROTECT STATE (3)
LOAD DATA XX
TO
ANY ADDRESS (4)
LOAD LAST BYTE
TO
LAST ADDRESS
Software Protected Write Cycle Waveforms (1, 2)
Notes: 1. A6 through A12 must specify the same page address during each high to low transition of WE (or CE) after
the software code has been entered.
2. OE must be high only when WE and CE are both low.
2-274
AT28HC64B
AT28HC64B
Data Polling Characteristics (1)
Symbol
Parameter
tDH
Data Hold Time
tOEH
OE Hold Time
Min
Typ
Max
Units
0
ns
0
ns
(2)
tOE
OE to Output Delay
tWR
Write Recovery Time
ns
0
Notes: 1. These parameters are characterized and not 100% tested.
ns
2. See AC Read Characteristics.
Data Polling Waveforms
Toggle Bit Characteristics (1)
Symbol
Parameter
tDH
Data Hold Time
tOEH
OE Hold Time
Min
Typ
Max
Units
10
ns
10
ns
(2)
tOE
OE to Output Delay
tOEHP
OE High Pulse
tWR
Write Recovery Time
ns
150
ns
0
ns
Notes: 1. These parameters are characterized and not 100% tested.
2. See AC Read Characteristics.
Toggle Bit Waveforms (1, 2, 3)
Notes: 1. Toggling either OE or CE or both OE and CE will
operate toggle bit.
2. Beginning and ending state of I/O6 will vary.
3. Any address location may be used, but the
address should not vary.
2-275
2-276
AT28HC64B
AT28HC64B
Ordering Information (1)
tACC
ICC (mA)
Ordering Code
Package
0.1
AT28HC64B-55JC
AT28HC64B-55PC
AT28HC64B-55SC
32J
28P6
28S
Commercial
(0°C to 70°C)
40
0.1
AT28HC64B-70JC
AT28HC64B-70PC
AT28HC64B-70SC
AT28HC64B-70TC
32J
28P6
28S
28T
Commercial
(0°C to 70°C)
40
0.1
AT28HC64B-70JI
AT28HC64B-70PI
AT28HC64B-70SI
AT28HC64B-70TI
32J
28P6
28S
28T
Industrial
(-40°C to 85°C)
40
0.1
AT28HC64B-90JC
AT28HC64B-90PC
AT28HC64B-90SC
AT28HC64B-90TC
32J
28P6
28S
28T
Commercial
(0°C to 70°C)
40
0.1
AT28HC64B-90JI
AT28HC64B-90PI
AT28HC64B-90SI
AT28HC64B-90TI
32J
28P6
28S
28T
Industrial
(-40°C to 85°C)
40
0.1
AT28HC64B-12JC
AT28HC64B-12PC
AT28HC64B-12SC
AT28HC64B-12TC
32J
28P6
28S
28T
Commercial
(0°C to 70°C)
40
0.1
AT28HC64B-12JI
AT28HC64B-12PI
AT28HC64B-12SI
AT28HC64B-12TI
32J
28P6
28S
28T
Industrial
(-40°C to 85°C)
(ns)
Active
Standby
55
40
70
90
120
Note:
Operation Range
1. See Valid Part Number table below.
2-277
Valid Part Numbers
The following table lists standard Atmel products that can be ordered.
Device Numbers
Speed
Package and Temperature Combinations
AT28HC64B
55
PC, SC
AT28HC64B
70
JI, PC, PI, SC, SI, TC, TI
AT28HC64B
90
JI, PC, PI, SC, SI, TC, TI
AT28HC64B
12
JI, PC, PI, SC, SI, TC, TI
Package Type
32J
32 Lead, Plastic J-Leaded Chip Carrier (PLCC)
28P6
28 Lead, 0.600" Wide, Plastic Dual Inline Package (PDIP)
28S
28 Lead, 0.300" Wide, Plastic Gull Wing Small Outline (SOIC)
28T
28 Lead, Plastic Thin Small Outline Package (TSOP)
2-278
AT28HC64B
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