Features
•
Single-voltage Operation
•
•
•
– 5V Read
– 5V Reprogramming
Fast Read Access Time - 55 ns
Internal Program Control and Timer
Sector Architecture
– One 16K Byte Boot Block with Programming Lockout
– Two 8K Byte Parameter Blocks
– Two Main Memory Blocks (96K, 128K Bytes)
Fast Erase Cycle Time - 10 seconds
Byte-by-byte Programming - 10 µs/Byte Typical
Hardware Data Protection
DATA Polling for End of Program Detection
Low Power Dissipation
– 50 mA Active Current
– 100 µA CMOS Standby Current
Typical 10,000 Write Cycles
•
•
•
•
•
•
2-megabit
(256K x 8)
5-volt Only
Flash Memory
AT49F002
AT49F002N
AT49F002T
AT49F002NT
Not Recommended
for New Design
Contact
Atmel to discuss
the latest design in trends
and options
Description
The AT49F002(N)(T) is a 5-volt only in-system reprogrammable Flash memory. Its 2
megabits of memory is organized as 262,144 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 275 mW over the commercial temperature range.
(continued)
Pin Configurations
Pin Name
A0 - A17
CE
OE
WE
RESET
I/O0 - I/O7
DC
Function
Addresses
Chip Enable
Output Enable
Write Enable
RESET
Data Inputs/Outputs
Don’t Connect
PLCC Top View
A12
A15
A16
RESET *
VCC
WE
A17
DIP Top View
* RESET
A16
A15
A12
A7
A6
A5
A4
A3
A2
A1
A0
I/O0
I/O1
I/O2
GND
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
VCC
WE
A17
A14
A13
A8
A9
A11
OE
A10
CE
I/O7
I/O6
I/O5
I/O4
I/O3
VSOP Top View (8 x 14 mm) or
TSOP Top View (8 x 20 mm)
Type 1
A11
A9
A8
A13
A14
A17
WE
VCC
* RESET
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
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
29
28
27
26
25
24
23
22
21
A14
A13
A8
A9
A11
OE
A10
CE
I/O7
Rev. 1017D–10/99
*Note: This pin is a DC on the AT49F002(N)(T).
1
When the device is deselected, the CMOS standby current
is less than 100 µA. For the AT49F002N(T) pin 1 for the
DIP and PLCC packages and pin 9 for the TSOP package
are don’t connect pins.
To allow for simple in-system reprogrammability, the
AT49F002(N)(T) does not require high input voltages for
programming. Five-volt-only commands determine the read
and programming operation of the device. Reading data
out of the device is similar to reading from an EPROM; it
has standard CE, OE, and WE inputs to avoid bus conten-
tion. Reprogramming the AT49F002(N)(T) is performed by
erasing a block of data and then programming on a byte by
byte basis. The byte programming time is a fast 50 µs. The
end of a program cycle can be optionally detected by the
DATA polling feature. Once the end of a byte program
cycle has been detected, a new access for a read or pro-
gram can begin. The typical number of program and erase
cycles is in excess of 10,000 cycles.
The device is erased by executing the erase command
sequence; the device internally controls the erase opera-
tions. There are two 8K byte parameter block sections and
two main memory blocks.
The device has the capability to protect the data in the boot
block; this feature is enabled by a command sequence.
The 16K-byte boot block section includes a reprogramming
lock out feature to provide data integrity. The boot sector is
designed to contain user secure code, and when the fea-
ture is enabled, the boot sector is protected from being
reprogrammed.
In the AT49F002(N)(T), once the boot block programming
lockout feature is enabled, the contents of the boot block
are permanent and cannot be changed. In the
AT49F002(T), once the boot block programming lockout
feature is enabled, the contents of the boot block cannot be
changed with input voltage levels of 5.5 volts or less.
Block Diagram
AT49F002(N)
DATA INPUTS/OUTPUTS
I/O7 - I/O0
VCC
GND
OE
WE
CE
RESET
8
INPUT/OUTPUT
BUFFERS
PROGRAM
DATA LATCHES
Y-GATING
3FFFF
X DECODER
MAIN MEMORY
BLOCK 2
(128K BYTES)
MAIN MEMORY
BLOCK 1
(96K BYTES)
PARAMETER
BLOCK 2
(8K BYTES)
PARAMETER
BLOCK 1
(8K BYTES)
BOOT BLOCK
(16K BYTES)
BOOT BLOCK
(16K BYTES)
20000
1FFFF
PARAMETER
BLOCK 1
(8K BYTES)
PARAMETER
BLOCK 2
(8K BYTES)
MAIN MEMORY
BLOCK 1
(96K BYTES)
MAIN MEMORY
BLOCK 2
(128K BYTES)
AT49F002(N)T
DATA INPUTS/OUTPUTS
I/O7 - I/O0
8
INPUT/OUTPUT
BUFFERS
PROGRAM
DATA LATCHES
Y-GATING
3FFFF
3C000
3BFFF
CONTROL
LOGIC
Y DECODER
ADDRESS
INPUTS
08000
07FFF
3A000
39FFF
06000
05FFF
38000
37FFF
04000
03FFF
00000
20000
1FFFF
00000
2
AT49F002(N)(T)
AT49F002(N)(T)
Device Operation
READ:
The AT49F002(N)(T) is accessed like an EPROM.
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 whenever CE or OE is high. This dual-line
control gives designers flexibility in preventing bus conten-
tion.
COMMAND SEQUENCES:
When the device is first pow-
ered on it will be reset to the read or standby mode
depending upon the state of the control line inputs. In order
to perform other device functions, a series of command
sequences are entered into the device. The command
sequences are shown in the Command Definitions table.
The command sequences are written by applying a low
pulse on the WE or CE input with CE or WE low (respec-
tively) and OE high. 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. Standard
microprocessor write timings are used. The address loca-
tions used in the command sequences are not affected by
entering the command sequences.
RESET:
A RESET input pin is provided to ease some sys-
tem applications. When RESET is at a logic high level, the
device is in its standard operating mode. A low level on the
RESET input halts the present device operation and puts
the outputs of the device in a high impedance state. If the
RESET pin makes a high to low transition during a program
or erase operation, the operation may not be successfully
completed and the operation will have to be repeated after
a high level is applied to the RESET pin. When a high level
is reasserted on the RESET pin, the device returns to the
read or standby mode, depending upon the state of the
control inputs. By applying a 12V
±
0.5V input signal to the
RESET pin, the boot block array can be reprogrammed
even if the boot block lockout feature has been enabled
(see Boot Block Programming Lockout Override section).
The RESET feature is not available for the AT49F002N(T).
ERASURE:
Before a byte can be reprogrammed, the main
memory block or parameter block which contains the byte
must be erased. The erased state of the memory bits is a
logical “1”. The entire device can be erased at one time by
using a 6-byte software code. The software chip erase
code consists of 6-byte load commands to specific address
locations with a specific data pattern (please refer to the
Chip Erase Cycle Waveforms).
After the software chip erase has been initiated, the device
will internally time the erase operation so that no external
clocks are required. The maximum time needed to erase
the whole chip is t
EC
. If the boot block lockout feature has
been enabled, the data in the boot sector will not be
erased.
CHIP ERASE:
If the boot block lockout has been enabled,
the Chip Erase function will erase Parameter Block 1,
Parameter Block 2, Main Memory Block 1, and Main Mem-
ory Block 2 but not the boot block. If the Boot Block Lockout
has not been enabled, the Chip Erase function will erase
the entire chip. After the full chip erase the device will
return back to read mode. Any command during chip erase
will be ignored.
SECTOR ERASE:
As an alternative to a full chip erase, the
device is organized into sectors that can be individually
erased. There are two 8K-byte parameter block sections
and two main memory blocks. The 8K-byte parameter
block sections can be independently erased and repro-
grammed. The two main memory sections are designed to
be used as alternative memory sectors. That is, whenever
one of the blocks has been erased and reprogrammed, the
other block should be erased and reprogrammed before
the first block is again erased. The Sector Erase command
is a six bus cycle operation. The sector address is latched
on the falling WE edge of the sixth cycle while the 30H data
input command is latched at the rising edge of WE. The
sector erase starts after the rising edge of WE of the sixth
cycle. The erase operation is internally controlled; it will
automatically time to completion.
BYTE PROGRAMMING:
Once the memory array is
erased, the device is programmed (to a logical “0”) on a
byte-by-byte basis. Please note that a data “0” cannot be
programmed back to a “1”; only erase operations can con-
vert “0”s to “1”s. Programming is accomplished via the
internal device command register and is a 4 bus cycle
operation (please refer to the Command Definitions table).
The device will automatically generate the required internal
program pulses.
The program cycle has addresses latched on the falling
edge of WE or CE, whichever occurs last, and the data
latched on the rising edge of WE or CE, whichever occurs
first. Programming is completed after the specified t
BP
cycle
time. The DATA polling feature may also be used to indicate
the end of a program cycle.
BOOT BLOCK PROGRAMMING LOCKOUT:
The device
has one designated block that has a programming lockout
feature. This feature prevents programming of data in the
designated block once the feature has been enabled. The
size of the block is 16K bytes. This block, referred to as the
boot block, can contain secure code that is used to bring up
the system. Enabling the lockout feature will allow the boot
code to stay in the device while data in the rest of the
device is updated. This feature does not have to be acti-
vated; the boot block’s usage as a write protected region is
optional to the user. The address range of the boot block is
00000 to 03FFF for the AT49F002(N) while the address
3
range of the boot block is 3C000 to 3FFFF for the
AT49F002(N)T.
Once the feature is enabled, the data in the boot block can
no longer be erased or programmed with input voltage lev-
els of 5.5V or less. Data in the main memory block can still
be changed through the regular programming method. To
activate the lockout feature, a series of six program com-
mands to specific addresses with specific data must be
performed. Please refer to the Command Definitions table.
BOOT BLOCK LOCKOUT DETECTION:
A software
method is available to determine if programming of the boot
block section is locked out. When the device is in the soft-
ware product identification mode (see Software Product
Identification Entry and Exit sections) a read from address
location 00002H will show if programming the boot block is
locked out for the AT49F002(N), and a read from address
location 3C002H will show if programming the boot block is
locked out for AT49F002(N)T. If the data on I/O0 is low, the
boot block can be programmed; if the data on I/O0 is high,
the program lockout feature has been activated and the
block cannot be programmed. The software product identi-
fication exit code should be used to return to standard
operation.
BOOT BLOCK PROGRAMMING LOCKOUT OVERRIDE:
The user can override the boot block programming lockout
by taking the RESET pin to 12 volts. By doing this, pro-
tected boot block data can be altered through a chip erase,
sector erase or word programming. When the RESET pin is
brought back to TTL levels the boot block programming
lockout feature is again active. This feature is not available
on the AT49F002N(T).
PRODUCT IDENTIFICATION:
The product identification
mode identifies the device and manufacturer as Atmel. It
may be accessed by hardware or software operation. The
hardware operation mode can be used by an external pro-
grammer to identify the correct programming algorithm for
the Atmel product.
For details, see Operating Modes (for hardware operation)
or Software Product Identification. The manufacturer and
device code is the same for both modes.
DATA POLLING:
The AT49F002(N)(T) features DATA poll-
ing to indicate the end of a program cycle. During a pro-
gram cycle an attempted read of the last byte loaded will
result in the complement of the loaded data on I/O7. Once
the program cycle has been completed, true data is valid
on all outputs and the next cycle may begin. DATA polling
may begin at any time during the program cycle.
T O G G L E B I T :
I n a d d i t i o n t o DATA p o l l i n g t h e
AT49F002(N)(T) provides another method for determining
the end of a program or erase cycle. During a program or
erase operation, successive attempts to read data from the
device will result in I/O6 toggling between one and zero.
Once the program cycle has completed, I/O6 will stop tog-
gling and valid data will be read. Examining the toggle bit
may begin at any time during a program cycle.
HARDWARE DATA PROTECTION:
Hardware features
protect against inadvertent programs to the
AT49F002(N)(T) in the following ways: (a) V
CC
sense: if
V
CC
is below 3.8V (typical), the program function is inhib-
ited. (b) Program inhibit: holding any one of OE low, CE
high or WE high inhibits program cycles. (c) Noise filter:
pulses of less than 15 ns (typical) on the WE or CE inputs
will not initiate a program cycle.
4
AT49F002(N)(T)
AT49F002(N)(T)
Command Definition (in Hex)
(1)
Command
Sequence
Read
Chip Erase
Sector Erase
Byte Program
Boot Block Lockout
(2)
Product ID Entry
Product ID Exit
(3)
Product ID Exit
(3)
Notes:
Bus
Cycles
1
6
6
4
6
3
3
1
1st Bus
Cycle
Addr
Addr
5555
5555
5555
5555
5555
5555
XXXX
Data
D
OUT
AA
AA
AA
AA
AA
AA
F0
2AAA
2AAA
2AAA
2AAA
2AAA
2AAA
55
55
55
55
55
55
5555
5555
5555
5555
5555
5555
80
80
A0
80
90
F0
5555
5555
Addr
5555
AA
AA
D
IN
AA
2AAA
55
5555
40
2AAA
2AAA
55
55
5555
SA
(4)
10
30
2nd Bus
Cycle
Addr
Data
3rd Bus
Cycle
Addr
Data
4th Bus
Cycle
Addr
Data
5th Bus
Cycle
Addr
Data
6th Bus
Cycle
Addr
Data
1. The DATA FORMAT in each bus cycle is as follows: I/O7 - I/O0 (Hex)
2. The 16K byte boot sector has the address range 00000H to 03FFFH for the AT49F002(N) and 3C000H to 3FFFFH for the
AT49F002(N)T
3. Either one of the Product ID Exit commands can be used.
4. SA = sector addresses:
For the AT49F002(N):
SA = 00000 to 03FFF for BOOT BLOCK
Nothing will happen and the device goes back to the read mode in 100 ns
SA = 04000 to 05FFF for PARAMETER BLOCK 1
SA = 06000 to 07FFF for PARAMETER BLOCK 2
SA = 08000 to 1FFFF for MAIN MEMORY ARRAY BLOCK 1
This command will erase - PB1, PB2 and MMB1
SA = 20000 to 3FFFF for MAIN MEMORY ARRAY BLOCK 2
For the AT49F002(N)T:
SA = 3C000 to 3FFFF for BOOT BLOCK
Nothing will happen and the device goes back to the read mode in 100 ns
SA = 3A000 to 3BFFF for PARAMETER BLOCK 1
SA = 38000 to 39FFF for PARAMETER BLOCK 2
SA = 20000 to 37FFF for MAIN MEMORY ARRAY BLOCK 1
This command will erase - PB1, PB2 and MMB1
SA = 00000 to IFFFF for MAIN MEMORY ARRAY BLOCK 2
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
with Respect to Ground ...................................-0.6V to +13.5V
*NOTICE:
Stresses beyond those listed under “Absolute Maxi-
mum 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 condi-
tions beyond those indicated in the operational sec-
tions of this specification is not implied. Exposure to
absolute maximum rating conditions for extended
periods may affect device reliability.
5
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