Features

Low Voltage Operation

2.7V Read
5V Program/Erase

Fast Read Access Time - 120 ns

Internal Erase/Program Control

Sector Architecture

One 8K Words (16K bytes) Boot Block with Programming Lockout
Two 8K Words (16K bytes) Parameter Blocks
One 104K Words (208K bytes) Main Memory Array Block

Fast Sector Erase Time - 10 seconds

Word-By-Word Programming - 10 µs/Word

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

Description

The AT49BV2048 and AT49LV2048 are 3-volt, 2-megabit Flash Memories organized
as 128K words of 16 bits each. Manufactured with Atmel's advanced nonvolatile
CMOS technology, the devices offer access times to 120 ns with power dissipation of
just 67 mW at 2.7V read. When deselected, the CMOS standby current is less than 50 µA.

2-Megabit
(128K x 16)
3-volt Only
Flash Memory

AT49BV2048
AT49LV2048
Preliminary

Rev. 0853C12/98

Pin Configurations

Pin Name

Function

A0 - A16

Addresses

Chip Enable

Output Enable

Write Enable

RESET

Reset

VPP

Program/Erase Power Supply

I/O0 - I/O15

Data Inputs/Outputs

No Connect

TSOP Top View

Type1

A15

A14

A13

A12

A11

A10

RESET

VPP

A16

GND

I/O15

I/O7

I/O14

I/O6

I/O13

I/O5

I/O12

I/O4

VCC

I/O11

I/O3

I/O10

I/O2

I/O9

I/O1

I/O8

I/O0

GND

SOIC (SOP)

VPP

GND

I/O0

I/O8

I/O1

I/O9

I/O2

I/O10

I/O3

I/O11

RESET

A10

A11

A12

A13

A14

A15

A16

GND

I/O15

I/O7

I/O14

I/O6

I/O13

I/O5

I/O12

I/O4

VCC

(continued)

AT49BV/LV2048

To allow for simple in-system reprogrammability, the
AT49BV2048/LV2048 does not require high input voltages
for programming. Reading data out of the device is similar
to reading from an EPROM; it has standard CE, OE, and
WE inputs to avoid bus contention. Reprogramming the
AT49BV2048/LV2048 is performed by first erasing a block
of data and then programming on a word-by-word basis.

The device is erased by executing the erase command
sequence; the device internally controls the erase opera-
tion. The memory is divided into three blocks for erase
operations. There are two 8K word parameter block sec-
tions and one sector consisting of the boot block and the
main memory array block. The AT49BV2048/LV2048 is
programmed on a word-by-word basis.

The device has the capability to protect the data in the boot
block; this feature is enabled by a command sequence.
Once the boot block programming lockout feature is
enabled, the data in the boot block cannot be changed
when input levels of 3.6 volts or less are used. The typical
number of program and erase cycles is in excess of 10,000
cycles.

The optional 8K word boot block section includes a repro-
gramming 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 protected
from being reprogrammed.

During a chip erase, sector erase, or word programming,
the V

pin must be at 5V

10%.

Block Diagram

Device Operation

READ: The AT49BV2048/LV2048 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 pre-
venting bus contention.

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
(I/O8 - I/O15 are don't care inputs for the command codes).
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. 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 repro-
grammed even if the boot block program lockout feature
has been enabled (see Boot Block Programming Lockout
Override section).

AT49BV/LV2048

ERASURE: Before a word can be reprogrammed, it must
be erased. The erased state of memory bits is a logical "1".
The entire device can be erased by using the Chip Erase
command or individual sectors can be erased by using the
Sector Erase commands.

CHIP ERASE: The entire device can be erased at one time
by using the 6-byte chip erase software code. After the chip
erase has been initiated, the device will internally time the
erase operation so that no external clocks are required.
The maximum time to erase the chip is t

If the boot block lockout has been enabled, the Chip Erase
will not erase the data in the boot block; it will erase the
main memory block and the parameter blocks only. After
the chip erase, the device will return to the read or standby
mode.

SECTOR ERASE: As an alternative to a full chip erase, the
device is organized into three sectors that can be individu-
ally erased. There are two 8K word parameter block sec-
tions and one sector consisting of the boot block and the
main memory array block. 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. When the boot block pro-
gramming lockout feature is not enabled, the boot block
and the main memory block will erase together (from the
same sector erase command). Once the boot region has
been protected, only the main memory array sector will
erase when its sector erase command is issued. Whenever
a parameter block is erased and reprogrammed, the other
parameter block should be erased and reprogrammed
before the first parameter block is erased again.

WORD PROGRAMMING: Once a memory block is erased,
it is programmed (to a logical "0") on a word-by-word basis.
Programming is accomplished via the internal device com-
mand register and is a 4 bus cycle operation. The device
will automatically generate the required internal program
pulses.

Any commands written to the chip during the embedded
programming cycle will be ignored. If a hardware reset hap-
pens during programming, the data at the location being
programmed will be corrupted. Please note that a data "0"
cannot be programmed back to a "1"; only erase operations
can convert "0"s to "1"s. Programming is completed after
the specified t

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 8K words. 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
00000H to 01FFFH.

Once the feature is enabled, the data in the boot block can
no longer be erased or programmed when input levels of
5.5V or less are used. 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
commands 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. 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 enabled and the block cannot be pro-
grammed. The software product identification 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

0.5 volts. By doing this

protected 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.

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 AT49BV2048/LV2048 features DATA
polling 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. During a chip
or sector erase operation, an attempt to read the device will
give a "0" on I/O7. Once the program or erase cycle has
completed, true data will be read from the device. 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 DATA p o l l i n g t h e
AT49BV2048/LV2048 provides another method for deter-

AT49BV/LV2048

mining the end of a program or erase cycle. During a pro-
gram 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
toggling and valid data will be read. Examining the toggle
bit may begin at any time during a program cycle.

HARDWARE DATA PROTECTION: Hardware features
p r o t e c t a g a i n s t i n a d v e r t e n t p r o g r a m s t o t h e
AT49BV2048/LV2048 in the following ways: (a) V

sense:

if V

is below 1.8V (typical), the program function is inhib-

ited. (b) V

power on delay: once V

has reached the

sense level, the device will automatically time out 10

ms (typical) before programming. (c) Program inhibit: hold-
ing any one of OE low, CE high or WE high inhibits pro-
gram cycles. (d) Noise filter: pulses of less than 15 ns
(typical) on the WE or CE inputs will not initiate a program
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 V

+ 0.6V.

Notes:

1. The Data Format in each bus cycle is as follows:

I/O15 - I/O8 (Don't care); I/O7 - I/O0 (Hex)

2. The 8K word boot sector has the address range 00000H to 01FFFH.

3. Either one of the product ID Exit commands can be used.

4. SA = sector addresses:

SA = 03XXX for PARAMETER BLOCK 1
SA = 05XXX for PARAMETER BLOCK 2
SA = 1FXXX for MAIN MEMORY ARRAY

5. When the boot block programming lockout feature is not enabled, the boot block and the main memory block will erase.

Command Definition (in Hex)

(1)

Command
Sequence

Bus
Cycles

1st Bus

Cycle

2nd Bus

Cycle

3rd Bus

Cycle

4th Bus

Cycle

5th Bus

Cycle

6th Bus

Cycle

Addr

Data

Addr

Data

Addr

Data

Addr

Data

Addr

Data

Addr

Data

Read

Addr

OUT

Chip Erase

5555

2AAA

5555

2AAA

5555

Sector Erase

5555

2AAA

5555

2AAA

(4)(5)

Word Program

5555

2AAA

5555

Addr

Boot Block Lockout

(2)

5555

2AAA

5555

2AAA

5555

Product ID Entry

5555

2AAA

5555

Product ID Exit

(3)

5555

2AAA

5555

Product ID Exit

(3)

xxxx

Absolute Maximum Ratings*

Operating Temperature ................................. -55°C to +125°C

*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 ..................................... -65°C to +150°C

Voltage on Any Pin
with Respect to Ground .....................................-1.0V to +7.0V

Maximum Operating Voltage............................................. 6.6V

DC Output Current...................................................... 25.0 mA

AT49BV/LV2048

Notes:

1. X can be V

or V

2. Refer to AC Programming Waveforms.

3. VH = 12.0V

0.5V.

4. Manufacturing Code: 1FH, Device Code: 82H

5. See details under Software Product Identification Entry/Exit.

Note:

1. In the erase mode, I

is 50 mA.

DC and AC Operating Range

AT49LV2048-12

AT49BV/LV2048-15

AT49BV/LV2048-20

Operating
Temperature (Case)

Com.

C - 70

Ind.

-40

C - 85

-40

C - 85

-40

C - 85

Power Supply

AT49LV2048

3.0V to 3.6V

AT49BV2048

N/A

2.7V to 3.6V

Operating Modes

Mode

RESET

I/O

Read

OUT

Program/Erase

(2)

10%

Standby/Program Inhibit

(1)

High Z

Program Inhibit

Output Disable

High Z

Reset

High Z

Product Identification

Hardware

A1 - A16 = V

, A9 = V

(3)

A0 = V

Manufacturer Code

(4)

A1 - A16 = V

, A9 = V

(3)

A0 = V

Device Code

(4)

Software

(5)

A0 = V

, A1 - A16 = V

Manufacturer Code

(4)

A0 = V

, A1 - A16 = V

Device Code

(4)

DC Characteristics

Symbol

Parameter

Condition

Min

Max

Units

Input Load Current

= 0V to V

µA

Output Leakage Current

I/O

= 0V to V

µA

SB1

Standby Current CMOS

CE = V

- 0.3V to V

µA

SB2

Standby Current TTL

CE = 2.0V to V

(1)

Active Current

f = 5 MHz; I

OUT

= 0 mA

Input Low Voltage

0.8

Input High Voltage

2.0

Output Low Voltage

= 2.1 mA

0.45

Output High Voltage

= -400 µA

2.4

Part Number AT49BV2048