W49F002U

256K

8 CMOS FLASH MEMORY

Publication Release Date: April 2000

- 1 - Revision A2

GENERAL DESCRIPTION

The W49F002U is a 2-megabit, 5-volt only CMOS flash memory organized as 256K

8 bits. The

device can be programmed and erased in-system with a standard 5V power supply. A 12-volt V

not required. The unique cell architecture of the W49F002U results in fast program/erase operations

with extremely low current consumption (compared to other comparable 5-volt flash memory

products). The device can also be programmed and erased using standard EPROM programmers.

FEATURES

Single 5-volt operations:

5-volt Read

5-volt Erase

5-volt Program

Fast Program operation:

Byte-by-Byte programming: 35

S (typ.)

Fast Erase operation: 100 mS (typ.)

Fast Read access time: 70/90/120 nS

Endurance: 10K cycles (typ.)

Ten-year data retention

Hardware data protection

One 16K byte Boot Block with Lockout

protection

Two 8K byte Parameter Blocks

Two Main Memory Blocks (96K, 128K) Bytes

Low power consumption

Active current: 25 mA (typ.)

Standby current: 20

A (typ.)

Automatic program and erase timing with

internal V

generation

End of program or erase detection

Toggle bit

Data polling

Latched address and data

TTL compatible I/O

JEDEC standard byte-wide pinouts

Available packages: 32-pin DIP and 32-pin

TSOP and 32-pin-PLCC

W49F002U

- 2 -

PIN CONFIGURATIONS

DQ0

DQ1

DQ2

GND

A16

A15

A12

A14

A13

A11

A10

DQ7

DQ6

DQ5

DQ4

DQ3

A17

32-pin

DIP

RESET

DQ0

D
Q

G
N
D

D
Q

D
Q
4

D
Q
5

D
Q
6

A14

A13

A11

A10

DQ7

A
1
2

A
1
6

V
D
D

A
1
5

32-pin

PLCC

A
1
7

R
E
S
E
T

32-pin
TSOP

A15
A12

A7
A6
A5

A14

A13

A11

A16

A17

RESET

DQ0

DQ1

DQ2

GND

OE
A10

CE
DQ7
DQ6

DQ5

DQ4
DQ3

BLOCK DIAGRAM

CONTROL

OUTPUT
BUFFER

DECODER

A17

DQ0

DQ7

3FFFF

20000
1FFFF

38000
37FFF

3A000
39FFF

00000

3C000
3BFFF

RESET

PARAMETER

BLOCK2

8K BYTES

BOOT BLOCK
16K BYTES

PARAMETER
BLOCK1
8K BYTES

MAIN MEMORY

BLOCK2

128K BYTES

MAIN MEMORY

BLOCK1

96K BYTES

PIN DESCRIPTION

SYMBOL

PIN NAME

RESET

Reset

A17

Address Inputs

DQ0

DQ7

Data Inputs/Outputs

Chip Enable

Output Enable

Write Enable

Power Supply

GND

Ground

W49F002U

Publication Release Date: April 2000

- 3 - Revision A2

FUNCTIONAL DESCRIPTION

Read Mode

The read operation of the W49F002U is controlled by CE and OE, both of which have to be low for

the host to obtain data from the outputs. CE is used for device selection. When CE is high, the chip

is de-selected and only standby power will be consumed. OE is the output control and is used to gate

data from the output pins. The data bus is in high impedance state when either CE or OE is high.
Refer to the timing waveforms for further details.

Reset Operation

The reset input pin can be used in some application. When RESET pin is at high state, the device is

in normal operation mode. When RESET pin is at low state, it will halts the device and all outputs are

at high impedance state. As the high state re-asserted to the RESET pin, the device will return to

read or standby mode, it depends on the control signals. When the system drives the RESET pin low
for at least a period of 500 nS, the device immediately terminates any operation in progress duration

of the RESET pulse. The other function for RESET pin is temporary reset the boot block. By

applying the 12V to RESET pin, the boot block can be reprogrammed even though the boot block
lockout function is enabled.

Boot Block Operation

There is one 16K-byte boot block in this device, which can be used to store boot code. It is located in
the last 16K bytes with the address range of the boot block is 3C000(hex) to 3FFFF(hex).See
Command Code sequence for Boot Block Lockout Enable for the specific code. Once this feature is
set the data for the designated block cannot be erased or programmed (programming lockout); other
memory locations can be changed with the regular programming method. Once the boot block
programming lockout feature is activated, the chip erase function can no longer erase the boot block.

There is one condition that the lockout feature can be overridden. Just apply 12V to RESET pin, the
lockout feature will temporarily be inactivated and the block can be erased/programmed. Once the

RESET pin return to TTL level, the lockout feature will be activated again.

In order to detect whether the boot block feature is set on the 16K-bytes block, users can perform
software command code sequence: enter the product identification mode (see Command Codes for
Identification/Boot Block Lockout Detection for specific code), and then read from address "0002
(hex)". If the DQ

of output data is "1," the boot block programming lockout feature is activated; if the

DQ0

of output data is "0 ," the lockout feature is inactivated and the block can be

erased/programmed.
To return to normal operation, perform a three-byte command code sequence (or an alternate single-
byte command) to exit the identification mode. For the specific code, see Command Code for
Identification/Boot Block Lockout Detection.

Chip Erase Operation

The chip-erase mode can be initiated by a six-byte command code sequence. After the command
loading cycle, the device enters the internal chip erase mode, which is automatically timed and will be
completed as fast as 100 mS (typical). The host system is not required to provide any control or
timing during this operation. The entire memory array will be erased to FF hex. by the chip erase

W49F002U

- 4 -

operation if the boot block programming lockout feature is not activated. Once the boot block lockout
feature is activated, the whole chip erase function will erase the two main memory blocks and the two
parameter blocks but not the boot block. The device will automatically return to normal read mode
after the erase operation. Data polling and/or Toggle Bits can be used to detect end of erase cycle.

Sector Erase Operation

There are four sectors: two main memory blocks and two parameters blocks which can be erased
individually by initiating a six-byte command code sequence. Sector address is latched on the falling

edge of WE signal in the sixth cycle while the data input "30(hex)" is latched at the rising edge of WE
in this cycle. After the command loading cycle, the device enters the internal sector erase mode,
which is automatically timed and will be completed as fast as 100 mS (typical). The host system does
not require to provide any control or timing during this operation. The device will automatically return
to normal read mode after the erase operation. Data polling and/or Toggle Bits can be used to detect
the end of erase cycle.

When different sector address is loaded in the sixth cycle for sector erase command, the
correspondent sectors will be erased automatically; that these sections will be erased independedntly.
For detail sector to be erased information, please refer to the Table of Command Definition.

Program Operation

The W49F002U is programmed on a byte-by-byte basis. Program operation can only change logical
data "1" to logical data "0". The erase operation (changed entire data in two main memory blocks and
two parameter blocks and/or boot block from "0" to "1") is needed before programming.

The program operation is initiated by a 4-byte command code sequence (see Command Codes for
Byte Programming). The device will internally enter the program operation immediately after the byte-
program command is entered. The internal program timer will automatically time-out (50

S max. -

). Once completed, the device returns to normal read mode. Data polling and/or Toggle Bits can

be used to detect end of program cycle.

Hardware Data Protection

The integrity of the data stored in the W49F002U is also hardware protected in the following ways:

(1) Noise/Glitch Protection: A WE pulse of less than 15 nS in duration will not initiate a write cycle.

(2) V

Power Up/Down Detection: The programming operation is inhibited when V

is less than

2.5V typical.

(3) Write Inhibit Mode: Forcing OE low, CE high, or WE high will inhibit the write operation. This
prevents inadvertent writes during power-up or power-down periods.

(4) V

power-on delay: When V

has reached its sense level, the device will automatically time-out

5 mS before any write (erase/program) operation.

Data Polling (DQ

)- Write Status Detection

The W49F002U includes a data polling feature to indicate the end of a program or erase cycle.
When the W49F002U is in the internal program or erase cycle, any attempt to read DQ

of the last

byte loaded will receive the complement of the true data. Once the program or erase cycle is
completed, DQ

will show the true data. Note that DQ

will show logical "0" during the erase cycle,

and become logical "1" or true data when the erase cycle has been completed.

W49F002U

Publication Release Date: April 2000

- 5 - Revision A2

Toggle Bit (DQ

)- Write Status Detection

In addition to data polling, the W49F002U provides another method for determining the end of a
program cycle. During the internal program or erase cycle, any consecutive attempts to read DQ

will

produce alternating 0's and 1's. When the program or erase cycle is completed, this toggling between
0's and 1's will stop. The device is then ready for the next operation.

Product Identification

The product ID operation outputs the manufacturer code and device code. Programming equipment
automatically matches the device with its proper erase and programming algorithms.
The manufacturer and device codes can be accessed by software or hardware operation. In the
software access mode, a three-byte (or JEDEC 3-byte) command sequence can be used to access
the product ID. A read from address 0000H outputs the manufacturer code DA(hex). A read from
address 0001H outputs the device code 0B(hex). The product ID operation can be terminated by a
three-byte command code sequence or an alternate one-byte command code sequence (see
Command Definition table).

In the hardware access mode, access to the product ID is activated by forcing CE and OE low, WE
high, and raising A9 to 12 volts.

TABLE OF OPERATING MODES

Operating Mode Selection

= 12V

)

MODE

PINS

RESET

ADDRESS

DQ.

Read

Dout

Write

Din

Standby

High Z

Write Inhibit

High Z/DOUT

Output Disable

High Z

Reset Mode

High Z

Product ID

A0 = V

; A1

A17 = V

;

A9 = V

Manufacturer Code DA (Hex)

A0 = V

; A1

A17 = V

;

A9 = V

Device Code 0B (Hex)

Ð­Ð»ÐµÐºÑ‚Ñ€Ð¾Ð½Ð½Ñ‹Ð¹ ÐºÐ¾Ð¼Ð¿Ð¾Ð½ÐµÐ½Ñ‚: W49F002UT12B

ÐÐ»ÐµÐºÑ‚Ñ€Ð¾Ð½Ð½Ñ‹Ð¹ ÐºÐ¾Ð¼Ð¿Ð¾Ð½ÐµÐ½Ñ‚: W49F002UT12B