Features
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Single Voltage for Read and Write: 2.7V to 3.6V (BV), 3.0V to 3.6V (LV)
Fast Read Access Time - 120 ns
Internal Program Control and Timer
16K bytes Boot Block With Lockout
Fast Chip Erase Cycle Time - 10 seconds
Byte-by-Byte Programming - 30
µs/Byte
Typical
Hardware Data Protection
DATA Polling For End Of Program Detection
Low Power Dissipation
– 25 mA Active Current
– 50
µA
CMOS Standby Current
•
Typical 10,000 Write Cycles
•
Small Packaging
– 8 x 8 mm CBGA
– 8 x 14 mm V-TSOP
Description
The AT49BV/LV040 are 3-volt-only, 4-megabit Flash memories organized as 524,288
words of 8-bits each. Manufactured with Atmel’s advanced nonvolatile CMOS tech-
nology, the devices offer access times to 120 ns with power dissipation of just 90 mW
over the commercial temperature range. When the device is deselected, the CMOS
standby current is less than 50
µA.
The device contains a user-enabled “boot block” protection feature. Two versions of
the feature are available: the AT49BV/LV040 locates the boot block at lowest order
addresses (“bottom boot”); the AT49BV/LV040T locates it at highest order addresses
(“top boot”).
4-Megabit
(512K x 8)
Single 2.7-volt
Battery-Voltage
™
Flash Memory
AT49BV040
AT49BV040T
AT49LV040
AT49LV040T
AT49BV/LV040
(continued)
Pin Configurations
Pin Name
A0 - A18
CE
OE
WE
I/O0 - I/O7
Function
Addresses
Chip Enable
Output Enable
Write Enable
Data Inputs/Outputs
A
B
1
CBGA Top View
2
3
4
5
6
7
GND I/O6 VCC VCC I/O2 OE GND
A17 I/O7 I/O4 NC NC I/O0 CE
C
A10 NC I/O5 NC I/O3 I/O1 A0
D
A14 A13 A9
E
A16 A11 WE NC
F
A15 A12 A8
NC A18 A5
A2
A7
A4
A1
NC NC
A6
A3
PLCC Top View
V - TSOP Top View (8 x 14 mm) or
T - TSOP Top View (8 x 20 mm)
0679AX-A–9/97
1
To allow for simple in-system reprogrammability, the
AT49BV/LV040 does not require high input voltages for
programming. Three-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.
Reprogramming the AT49BV/LV040 is performed by eras-
ing the entire 4 megabits of memory and then programming
on a byte-by-byte basis. The typical byte programming
time is a fast 30
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 program can begin. The typical num-
ber of program and erase cycles is in excess of 10,000
cycles.
The optional 16K bytes boot block section includes a repro-
gramming write lock out feature to provide data integrity.
The boot sector is designed to contain user secure code,
and when the feature is enabled, the boot sector is perma-
nently protected from being reprogrammed.
Block Diagram
AT49BV/LV040
DATA INPUTS/OUTPUTS
I/O7 - I/O0
8
OE, CE, AND WE
LOGIC
DATA LATCH
INPUT/OUTPUT
BUFFERS
Y-GATING
7FFFFH
X DECODER
MAIN MEMORY
(496K BYTES)
03FFFH
OPTIONAL BOOT
BLOCK (16K BYTES)
00000H
MAIN MEMORY
(496K BYTES)
00000H
OPTIONAL BOOT
BLOCK (16K BYTES)
7C000H
AT49BV/LV040T
DATA INPUTS/OUTPUTS
I/O7 - I/O0
8
DATA LATCH
INPUT/OUTPUT
BUFFERS
Y-GATING
7FFFFH
V
CC
GND
OE
WE
CE
Y DECODER
ADDRESS
INPUTS
Device Operation
READ:
The AT49BV/LV040 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 con-
tention.
ERASURE:
Before a byte can be reprogrammed, the
512K bytes memory array (or 496K bytes if the boot block
featured is used) 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 com-
mands 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.
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 pro-
grammed back to a “1”; only erase operations can convert
2
“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 pro-
gram 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
AT49BV/LV040 boot block is 00000H to 03FFFH while the
address range of the AT49BV/LV040T boot block is
7C000H to 7FFFFH.
AT49BV/LV040
AT49BV/LV040
Once the feature is enabled, the data in the boot block can
no longer be erased or programmed. Data in the main
memory block can still be changed through the regular pro-
gramming method. To activate the lockout feature, a series
of six program commands to specific addresses with spe-
cific data must be performed. Please refer to the Com-
mand 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. If the data on I/O0 is low, the boot block can be
programmed; if the data on I/O0 is high, the program lock-
out feature has been activated and the block cannot be
programmed. The software product identification code
should be used to return to standard operation.
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
programmer 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 AT49BV/LV040 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.
TO G G L E B I T:
I n a d d i t i o n t o D A T A p o l l i n g t h e
AT49BV/LV040 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 AT49BV/LV040
in the following ways: (a) V
CC
sense: if V
CC
is below 1.8V
(typical), the program function is inhibited. (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 pro-
gram cycle.
INPUT LEVELS:
While operating with a 2.7V to 3.6V
power supply, the address inputs and control inputs (OE,
CE and WE) may be driven from 0 to 5.5V without
adversely affecting the operation of the device. The I/O
lines can only be driven from 0 to VCC + 0.6V.
3
Command Definition (in Hex)
Command
Sequence
Read
Chip Erase
Byte Program
Boot Block Lockout
(1)
Product ID Entry
Product ID Exit
(2)
Product ID Exit
(2)
Notes:
1.
2.
Bus
Cycles
1
6
4
6
3
3
1
1st Bus
Cycle
Addr
Addr
5555
5555
5555
5555
5555
XXXX
Data
D
OUT
AA
AA
AA
AA
AA
F0
2AAA
2AAA
2AAA
2AAA
2AAA
55
55
55
55
55
5555
5555
5555
5555
5555
80
A0
80
90
F0
5555
Addr
5555
AA
D
IN
AA
2AAA
55
5555
40
2AAA
55
5555
10
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
The 16K byte boot sector has the address range 00000H to 03FFFH for the AT49BV/LV040 and 7C000H to 7FFFFH for the
AT49BV/LV040T.
Either one of the Product ID exit commands can be used.
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.
4
AT49BV/LV040
AT49BV/LV040
DC and AC Operating Range
AT49BV/LV040-12
Operating
Temperature (Case)
V
CC
Power Supply
Com.
Ind.
0°C - 70°C
-40°C - 85°C
2.7V to 3.6V/3.0V to 3.6V
AT49BV/LV040-15
0°C - 70°C
-40°C - 85°C
2.7V to 3.6V/3.0V to 3.6V
AT49BV/LV040-20
0°C - 70°C
-40°C - 85°C
2.7V to 3.6V/3.0V to 3.6V
Operating Modes
Mode
Read
Program
(2)
Standby/Write Inhibit
Program Inhibit
Program Inhibit
Output Disable
Product Identification
A1 - A18 = V
IL
, A9 = V
H
,
(3)
A0 = V
IL
A1 - A18 = V
IL
, A9 = V
H
,
(3)
A0 = V
IH
A0 = V
IL
, A1 - A18 = V
IL
A0 = V
IH
, A1 - A18 = V
IL
Notes:
1.
2.
3.
4.
5.
X can be V
IL
or V
IH
.
Refer to AC Programming Waveforms.
V
H
= 12.0V
±
0.5V.
Manufacturer Code: 1FH
Device Code: 13H (AT49BV/LV040), 12H (AT49BV/LV040T).
See details under Software Product Identification Entry/Exit.
Manufacturer Code
(4)
Device Code
(4)
Manufacturer Code
(4)
Device Code
(4)
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
Ai
Ai
Ai
X
I/O
D
OUT
D
IN
High Z
Hardware
V
IL
V
IL
V
IH
Software
(5)
DC Characteristics
Symbol
I
LI
I
LO
I
SB1
I
SB2
I
CC(1)
V
IL
V
IH
V
OL
V
OH
Note:
1.
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
In the erase mode, I
CC
is 50 mA.
I
OL
= 2.1 mA
I
OH
= -100
µA;
V
CC
= 3.0V
2.4
2.0
0.45
Condition
V
IN
= 0V to V
CC
V
I/O
= 0V to V
CC
CE = V
CC
- 0.3V to V
CC
CE = 2.0V to V
CC
f = 5 MHz; I
OUT
= 0 mA, V
CC
= 3.6V
12
Min
Typ
Max
10
10
50
1
25
0.8
Units
µA
µA
µA
mA
mA
V
V
V
V
5
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