AMD Advanced Micro Devices AM29LV017B-90WCI, AM29LV017B-90WCEB, AM29LV017B-90WCE, AM29LV017B-90WCCB, AM29LV017B-90WCC Datasheet

...
PRELIMINARY
Am29LV017B
16 Megabit (2 M x 8-Bit) CMOS 3.0 Volt -only Uniform Sector Flash Memory

DISTINCTIVE CHARACTERISTICS

Single power supply operation
— Full voltage range: 2.7 to 3. 6 volt read and write
operations for battery-powered applications
— Regulated voltage range: 3.0 to 3. 6 volt read
and write operations and for compatibility with high performance 3.3 volt microprocessors
Embedded Algorithms
— Embedded Erase algorithm automatically
preprograms and erases the entire chip or any combination of designated sectors
— Embedded Program algorithm automatically
writes and verifies data at specified addresses
Manufactured on 0.35 µm process technology
High performance
— Full voltage range: ac cess times as f ast as 90 ns — Regulated voltage range: access times as fast
as 80 ns
Ultra low power consumption (typical values at
5 MHz)
— 200 nA Automatic Sleep mode current — 200 nA standby mode current — 9 mA read current — 15 mA program/erase current
Flexible sector architecture
— Thirty-two 64 Kbyte sectors — Supports full chip erase — Sector Protection features:
A hardware method of locking a sector to prevent any program or erase operations within that sector
Sectors can be locked in-system or via programming equipment
T emporary Sector Unprotect feat ure allows code changes in previously locked sectors
Unlock Bypass Program Command
— Reduces overall progr amming time when
issuing multiple program command sequences
Minimum 1,000,000 write cycle guarantee per
sector
Package option
— 48-ball FBGA — 40-pin TSOP
CFI (Common Flash Interface) compliant
— Provides device-specific information to the
system, allowing host software to easily reconfigure for different Flash devices
Compatibility with JEDEC standards
— Pinout and software compatible with single-
power supply Flash
— Superior inadvertent write protection
Data# Polling and toggle bits
— Provides a software method of detecting
program or erase operation completion
Ready/Busy# pin (RY/BY#)
— Provides a hardware method of detecting
program or erase cycle completion
Erase Suspend/Erase Resume
— Suspends an erase operati on to read dat a from,
or program data to, a sector that is not being erased, then resumes the erase operation
Hardware reset pin (RESET#)
— Hardware method to reset the de vi ce to reading
array data
This document contains information on a product under development at Advanced Micro Devices. The information is intended to help you ev aluate this product. AMD reserves the right to change or dis continue work on thi s proposed product without notice.
Publication# 21415 Rev: C Amendment/+2 Issue Date: March 1998
PRELIMINARY

GENERAL DESCRIPTION

The Am29LV017B is a 16 Mbit, 3.0 Volt-only Flash memory organized as 2,097,152 bytes. The device is offered in 48-ball FBGA and 40-pin TSOP p ackages.
The byte-wide (x8) data appears on DQ7–DQ0. All read, program, and erase operations are accomplished using only a single power supply. The device can also be programmed in standard EPROM programmers.
The standard device off ers access times of 80, 90, and 120 ns, allowing high speed microprocessors to operate without wait s tates. To eliminate bus conten­tion the device has separate chip enable (CE#), write enable (WE#) and output enable (OE#) controls.
The device requires only a single 3. 0 v o lt po wer sup- ply for both read and write functions. Internally gener­ated and regulated voltages are provided for the program and erase operations.
The device is entirely command set compatible with the JEDEC single-power-supply Flash standard. Com­mands are written to the command regis ter using standard micropr ocessor wri te timings. Register co n­tents serve as input to an internal state-machine that controls the erase and programming circuitry. Write cycles also internally latch addresses and data needed for the programming and erase operations. Reading data out of the device is similar to reading from other Flash or EPROM devices.
Device programming occurs by executing the program command sequence. This initiates the Embedded Program algorithm—an internal algorithm that auto­matically times the program pulse widths and verifies proper cell margin. The Unlock Bypass mode facili­tates faster programming times by requir ing only two write cycles to program data instead of four.
Device erasure occurs by executing the erase com­mand sequence. This initiates the Embedded Erase algorithm—an internal algorithm that automatically pre­programs the array (if it is not already progr ammed) be­fore executing the erase operation. During erase, the device automatically times the erase pulse widths and verifies proper cell margin.
The host system can detect whether a program or erase operation is complete by observing the RY/BY# pin, or by reading the DQ7 (Data# Polling) and DQ6 (toggle) status bits. After a program or erase cycle has been completed, the device is ready to read array data or accept another command.
The sector erase ar chitecture allo ws memo ry secto rs to be erased and reprogrammed without affecting the data contents of other sectors. The device is fully erased when shipped from the factory.
Hardware data protection measures include a low
detector that automatically in hibits write opera-
V
CC
tions during power transitions. The hardware sector protection feature disables both program and erase
operations in any combination of the sectors of mem­ory. This can be achieved in-system or via program­ming equipment.
The Erase Suspend feature enables the user to put erase on hold for any period of time to read data from, or program data to, any sector that is not selected for erasure. True background erase can thus be achieved.
The hardware RESET# pi n terminates any operation in progress and resets the internal state machine to reading array dat a. The RESET# pin ma y be tied to the system reset circuitry. A system reset would thus also reset the device, enabling the system microprocessor to read the boot-up firmware from the Flash memory.
The device offers two power-saving features. When addresses have been stable for a specified amount of time, the device enters the automatic sleep m ode. The system can also place the de vice into the standby mode. Power consumption is greatly reduced in both these modes.
AMD’s Flash technology combines years of Flash memory manufacturing experience to produce the highest levels of quality, reliability and cost effective­ness. The device electrically erases a ll bit s within a sector simultaneously via Fowler-Nordheim tun­neling. The data is programmed using hot electron injection.
Am29LV017B 2
PRELIMINARY

PRODUCT SELECTOR GUIDE

Family Part Number Am29LV017B
Speed Option
Max access time, ns (t Max CE# access time, ns (tCE) 80 90 120 Max OE# access time, ns (tOE) 30 35 50
Regulated Voltage Range: VCC =3.0–3.6 V -80R
Full Voltage Range: VCC = 2.7–3.6 V -90 -120
) 80 90 120
ACC
Note: See “AC Characteristics” for full specifications.

BLOCK DIAGRAM

DQ0
DQ7
Input/Output
Buffers
Data
Latch
V
CC
V
SS
RESET#
WE#
CE#
OE#
RY/BY#
State
Control
Command
Register
PGM Voltage
Generator
Sector Switches
Erase Voltage
Generator
Chip Enable
Output Enable
Logic
STB
A0–A20
VCC Detector
Timer
STB
Address Latch
Y-Decoder
X-Decoder
Y-Gating
Cell Matrix
21415C-1
3 Am29LV017B

CONNECTION DIAGRAMS

PRELIMINARY
A16 A15 A14 A13 A12 A11
A9 A8
WE#
RESET#
NC
RY/BY#
A18
A7 A6 A5 A4 A3 A2 A1
A17 V
SS
A20 A19
A10 DQ7 DQ6 DQ5 DQ4
V
CC
V
CC
NC DQ3 DQ2 DQ1 DQ0 OE#
V
SS
CE#
A0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
40-Pin Standard TSOP
40-Pin Reverse TSOP
40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21
40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21
A17 V
SS
A20 A19 A10 DQ7 DQ6 DQ5 DQ4 V
CC
V
CC
NC DQ3 DQ2 DQ1 DQ0 OE#
V
SS
CE# A0
A16 A15 A14 A13 A12 A11 A9 A8 WE# RESET# NC RY/BY# A18 A7 A6 A5 A4 A3 A2 A1
48-Ball FBGA (Bottom View)
A1 B1 A3 A4 A2 A1 A0 CE# OE# V
A2 B2C1C2D1D2E1E2F1F2G1G2 A7 A18 A6 A5 DQ0 NC NC DQ1
A3 B3 C3 D3 E3 F3 G3 H3
RY/BY# NC NC NC DQ2 DQ3 V
A4 B4 C4 D4 E4 F4 G4 H4
WE# RESET# NC NC DQ5 NC V
A5 B5 C5 D5 E5 F5 G5 H5 A9 A8 A11 A12 A19 A10 DQ6 DQ7
A6 B6 C6 D6 E6 F6 G6 H6
A14 A13 A15 A16 A17 NC A20 V
CC
CC
Am29LV017B 4
H1
SS
H2
NC
DQ4
SS
21415C-2
PRELIMINARY

Special Handling Instructions for FBGA Packages

Special handling is required for Flash Memory products in FBGA packages.

PIN CONFIGURATION

A0–A20 = 21 addresses DQ0–DQ7 = 8 data inputs/outputs CE# = Chip enable OE# = Output enable WE# = Write enable RESET# = Hardware reset pin, active low RY/BY# = Ready/Busy output
= 3.0 volt-only single power supply
V
CC
V
SS
NC = Pin not connected internally
(see Product Selector Guide for speed options and voltage supply toleranc es)
= Device ground
Flash memory devices in FBGA packages may be damaged if exposed to ultrasonic cleaning methods. The package and/or data integrity may be compromised if the package body is exposed to temperatures above 150°C for prolonged periods of time.

LOGIC SYMBOL

21
A0–A20
DQ0–DQ7
CE# OE#
WE# RESET#
RY/BY#
8
21415C-3
5 Am29LV017B
PRELIMINARY
ORDERING INFORMATION Standard Pr od ucts
AMD standard products are available in s everal packages and operating ranges. The order number (Valid Combi­nation) is formed by a combination of the elements below.
CE-80RAm29LV017B
OPTIONAL PROCESSING
Blank = Standard Pro ces sin g B = Burn-in (Contact an AMD representative for more information)
TEMPERATURE RANGE
C=Commercial (0°C to +70°C) I = Industrial (–40°C to +85°C) E = Extended (–55°C to +125°C)
PACKAGE TYPE
E = 40-Pin Thin Small Outline Package (TSOP)
Standard Pinout (TS 040)
F = 40-Pin Thin Small Outline Package (TSOP)
Reverse Pinout (TSR040)
WC = 48-ball Fine-Pitch Ball Grid Array (FBGA)
0.80 mm pitch, 8 x 9 mm package
DEVICE NUMBER/DESCRIPTION
Am29LV017B 16 Megabit (2 M x 8-Bit) CMOS Flash Memory
3.0 Volt-only Read, Program, and Erase
Valid Combinations
Am29LV017B-80R EC, FC, WCC Am29LV017B-90 EC, EI, EE,
Am29LV017B-120
FC, FI, FE,
WCC, WCI, WCE
SPEED OPTION
See Product Selector Guide and Valid Combinations
Valid Combinations
Valid Combinations list configurations planned to be sup­ported in volume for this device. Consult the local AMD sales office to confirm availability of specific valid combinations and to check on newly released combinations.
Am29LV017B 6
PRELIMINARY

DEVICE BUS OPERATIONS

This section describes the requirements and use of the device bus operations, which are initiated through the internal command register. The command register itself does not occupy any addressable memory loc ation. The register is composed of latches that store the com­mands, along with the address and data information needed to execute the command. The contents of the
Table 1. Am29LV017B Device Bus Operations
Operation CE# OE# WE# RESET# Addresses DQ0–DQ7
Read L L H H A Write L H L H A
Standby Output Disable L H H H X High-Z
Reset X X X L X High-Z Sector Protect (See Note) L H L V
Sector Unprotect (See Note) L H L V Temporary Sector Unprotect X X X V
Legend:
L = Logic Low = V
Note: The sector protect and sector unprotect functions may also be implemented via programming equipment. See the “Sector Protection/Unprotection” section.
, H = Logic High = VIH, VID = 12.0 ± 0.5 V, X = Don’t Care, AIN = Address In, DIN = Data In, D
IL
VCC ±
0.3 V
XX
register serve as inputs to the internal state machine. The state machine outputs d ictate the function of the device. Table 1 lists the device bus operations, the in­puts and control levels they require, and the resulting output. The following subsections describe each of these operations in further detail.
D
D
D
, D
IN
D
, D
IN
D
= Data Out
OUT
OUT
IN
OUT
OUT
IN
VCC ±
0.3 V
ID
ID
ID
IN IN
X High-Z
Sector Addresses,
A6 = L, A1 = H, A0 = L
Sector Addresses
A6 = H, A1 = H, A0 = L
A
IN

Requirements for Reading Array Data

To read array data from the outputs, the system must drive the CE# and OE# pins to V control and selects the dev ice. OE# is the output con­trol and gates array data to the output pins. WE# should remain at V
.
IH
The internal state machine is set for reading arr ay data upon device power-up, or after a hardware reset. This ensures that no spurious alteration of the memory con­tent occurs during the power transition. No command is necessary in this mode to obtain array data. Standard microprocessor read cycles that assert valid addresses on the device address input s produc e valid data on the device data outputs. The device remains enabled for read access until the command register contents are altered.
See “Reading Array Data” for more information. Refer to the AC Read Operations table for timing specifica­tions and to Figure 13 for the timing diagram. I
the DC Characteristics table represents the active cur­rent specification for reading array data.
. CE# is the power
IL
CC1
in

Writing Commands/Command Sequences

To write a command or command sequence (which in­cludes programming data to the device and erasing sectors of memory), the system must drive WE# and CE# to V
The device features an Unlock Bypass mode to facil- itate faster programming. Once the device enters the Unlock Bypass mode, only two write cycles are re­quired to program a byte, instead of four. The “Byte Program Command Sequence” section has details on programming data to the device using both standard and Unlock Bypass command sequences.
An erase operation can erase one sect or, multiple sec­tors, or the entire de vi ce. Table 2 indicat es the addres s space that each sector occupies. A “sector address” consists of the address bits required to uniquely select a sector. The “Command Definitions” section has de­tails on erasing a sector or the entire chip, or suspend­ing/resuming the erase operation.
After the system writes the autoselect command se­quence, the device enters the autoselect mode. The system can then read autoselect codes from the inter­nal register (which is separate from the memory array) on DQ7–DQ0. Standard read cycle timings apply in this
, and OE# to VIH.
IL
7 Am29LV017B
PRELIMINARY
mode. Refer to the Autoselect Mode and Autoselect Command Sequence sections for more information.
in the DC Characteristics table represents the ac-
I
CC2
tive current specification for the write m ode. The “AC
Characteristics” section contains timing specification tables and timing diagrams for w r ite operations.

Program and Erase Operation Status

During an erase or program operation, the system ma y check the status of the operation by reading the status bits on DQ7–DQ0. Standard read cycle timings and I
CC
read specifications apply. Refer to “Write Operation Status” for more information, and to “AC Characteris­tics” for timing diagrams.

Standby Mode

When the system is not reading or writing to the device , it can place the device in the standby mode. In this mode, current consumption is great ly reduc ed, and the outputs are placed in the high impedance state, inde­pendent of the OE# input.
The device enters the CMOS standby mode when the CE# and RESET# pin s are both held at V
CC
± 0.3 V.
(Note that this is a more restricted voltage range than
.) If CE# and RESET# ar e held a t VIH, but not within
V
IH
± 0.3 V, the device will be in the standb y mode, b ut
V
CC
the standby current will be greater. The device requires standard access time (t
) for read access when the
CE
device is in either of these standby modes, before it is ready to read data.
The device also enters the standb y mode when the RE­SET# pin is driven low. Refer to the next section, “RE­SET#: Hardware Reset Pin”.
If the device is deselected during erasure or program­ming, the device draws active current until the operation is completed.
in the DC Characteristics table represents the
I
CC3
standby current specification.

Automatic Sleep Mode

The automatic sleep mode minimizes Flash device energy consumption. The device automatically enables this mode when addres ses remain stable for
+ 30 ns. The automatic sleep mode is
t
ACC
independent of the CE#, WE#, and OE# control
signals. Standard address access timings provide new data when addresses are chan ged. While in sleep mode, output data is latched and always available to the system. I
in the DC Characteristics table
CC4
represents the automatic sleep mode current specification.

RESET#: Hardware Reset Pin

The RESET# pin provides a hardw are method of reset­ting the device to reading array data. When the RE­SET# pin is driven low for at least a period of t
RP
, the device immediately terminates any operation in progress, tristates all output pins, and ignores all read/write commands for the duration of the RESET# pulse. The device also resets the inter nal state ma­chine to reading array data. The operation that was in­terrupted should be reinitiated once the device is ready to accept another command sequence, to ensure data integrity.
Current is reduced for the duration of the RESET# pulse. When RESET# is held at V draws CMOS standby c urrent (I
but not within VSS±0.3 V, the standby current will
at V
IL
±0.3 V, the device
SS
). If RESET# is held
CC4
be greater. The RESET# pin may be tied to the system reset cir-
cuitry. A system reset would thus also reset the Flash memory, enabling the system to read the boot-up firmware from the Flash memory.
If RESET# is asserted during a program or erase oper­ation, the RY/BY# pin remains a “0” (busy) until the in­ternal reset operatio n is complete, which requires a time of t
(during Embedded Algorithms). The
READY
system can thus monitor RY/BY# to determine whether the reset operation is complete. If RESET# is asserted when a program or erase operation is not executing (RY/BY# pin is “1”), the reset operation is completed within a time of t rithms). The system can read data t SET# pin returns to V
(not during Embe dded Algo-
READY
.
IH
RH
after the RE-
Refer to the AC Characteristics tables for RESET# pa­rameters and to Figure 14 for the timing diagram.

Output Disable Mode

When the OE# input is at VIH, output from the device is disabled. The output pins are placed in t he high imped­ance state.
Am29LV017B 8
PRELIMINARY
Table 2. Am29LV017B Sector Address Table
Address Range
Sector A20 A19 A18 A17 A16
SA0 00000 000000–00FFF F SA1 00001 01000001FFFF SA2 00010 02000002FFFF SA3 00011 03000003FFFF SA4 00100 04000004FFFF SA5 00101 05000005FFFF SA6 00110 06000006FFFF SA7 00111 07000007FFFF SA8 01000 08000008FFFF
SA9 01001 09000009FFFF SA1001010 0A00000AFFFF SA1101011 0B00000BFFFF SA1201100 0C00000CFFFF SA1301101 0D00000DFFFF SA1401110 0E00000EFFFF SA1501111 0F00000FFFFF SA1610000 10000010FFFF SA1710001 11000011FFFF SA1810010 12000012FFFF SA1910011 13000013FFFF SA2010100 14000014FFFF SA2110101 15000015FFFF SA2210110 16000016FFFF SA2310111 17000017FFFF SA2411000 18000018FFFF SA2511001 19000019FFFF SA2611010 1A00001AFFFF SA2711011 1B00001BFFFF SA2811100 1C00001CFFFF SA2911101 1D00001DFFFF SA3011110 1E00001EFFFF SA3111111 1F00001FFFFF
(in hexadecimal)
9 Am29LV017B
PRELIMINARY

Autoselect Mode

The autoselect mode provides manufacturer and de­vice identification, and sector protection verification,
through identifier codes output on DQ7–DQ0. This mode is primarily intended for progr amming equipment to automatically match a device to be progr ammed with its correspondi ng programming al gorithm. However, the autoselect codes can also be accessed in-system through the command register.
When using programming equipment, the autoselect mode requires V A9. Address pins A6, A1, and A0 must be as shown in
(11.5 V to 12.5 V) on address pin
ID
Table 3. In addition, when verifying sector protec tion, the sector address must appear on the appropriate highest order address bits (see Table 2). Table 3 sho ws the remaining address bits that are don’t c are. When all necessary bits have been set as required, the program­ming equipment may then read the corresponding identifier code on DQ7-DQ0.
To access the autoselect codes in-system, the host system can issue the autoselect command via the command register, as shown in Table 8. This method does not require V details on using the autoselect mode.
Table 3. Am29LV017B Autoselect Codes (High Voltage Method)
A20
A15
to
to
Description CE# OE# WE#
Manufacturer ID: AMD L L H X X V Device ID: Am29LV0 17B L L H X X V
Sector Protection Verification L L H SA X V
A16
A10 A9
. See “Command Definitions” for
ID
A8
to
A7 A6
XLXLL 01h
ID
XLXLH C8h
ID
XLXHL
ID
A5
to
A2 A1 A0
DQ7
to
DQ0
01h
(protected)
00h
(unprotected)
L = Logic Low = VIL, H = Logic High = VIH, SA = Sector Address, X = Don’t care.

Sector Protection/Unprotection

The hardware sector protection feature disables both program and erase operations in any sect or. The hard­ware sector unprotection feature re-enables both pro-
through AMD’s ExpressFlash™ Servic e. Contact an AMD representative for details.
It is possible to determine whether a sector is protected or unprotected. See “Autoselect Mode” for details.
gram and erase operations in previously protected sectors. Sector protection/unprotecti on can be imple­mented via two methods.
The primary method requires V
on the RESET# pin
ID
only, and c an be implemented either in-system or via programming equipment. Figure 1 shows the algo­rithms and Figure 21 shows the timing diagram. This method uses standard m icroprocessor bus cycle tim­ing. For sector unprotect, all unprotected sectors must first be protected prior to the first sector unpro tect write cycle.

Temporary Sector Unprotect

This feature allows temporary unprotection of previ­ously protected sectors to change data in-system. The Sector Unprotect mode is activated by setting the RE­SET# pin to V sectors can be programmed or erased b y selecting the sector addresses. Once V SET# pin, all the previously protected sectors are protected again. Figure 2 shows the algorithm, and Figure 20 shows the tim ing diagrams, for this feature.
The alternate method intended on ly for programming equipment requires V
on address pin A9 and OE#.
ID
This method is compatible with programmer routines written for earlier 3.0 v olt-only AMD flash de vices. Pub­lication number 21587 contains further details; contact an AMD representative to request a copy.
. During this mode, formerly protected
ID
is removed from the RE-
ID
The device is shipped with all s ectors unprotected. AMD offers the option of programming and protecting sectors at its factory prior to shipping the device
Am29LV017B 10
PRELIMINARY
Temporary Sector
Unprotect Mode
Increment
PLSCNT
No
PLSCNT
= 25?
Yes
Device failed
Sector Protect
Algorithm
START
PLSCNT = 1
RESET# = V
Wait 1 µs
No
First Write
Cycle = 60h?
Set up sector
address
Sector Protect:
Write 60h to sector
address with
A6 = 0, A1 = 1,
A0 = 0
Wait 150 µs
Verify Sector
Protect: Write 40h
to sector address
with A6 = 0,
A1 = 1, A0 = 0
Read from
sector address
with A6 = 0,
A1 = 1, A0 = 0
No
Data = 01h?
Protect another
sector?
Remove V
from RESET#
Write reset
command
Sector Protect
complete
Yes
Yes
No
START
Protect all sectors:
The indicated portion
of the sector protect
ID
Reset
PLSCNT = 1
Yes
ID
algorithm must be
performed for all
unprotected sectors
prior to issuing the
first sector
unprotect address
Increment
PLSCNT
No
PLSCNT
= 1000?
Yes
Device failed
Sector Unprotect
PLSCNT = 1
RESET# = V
Wait 1 µs
First Write
Cycle = 60h?
No
All sectors protected?
Set up first sector
address
Sector Unprotect:
Write 60h to sector
address with
A6 = 1, A1 = 1,
A0 = 0
Wait 15 ms
Verify Sector
Unprotect: Write
40h to sector address with
A6 = 1, A1 = 1,
A0 = 0
Read from
sector address
with A6 = 1,
A1 = 1, A0 = 0
No
Data = 00h?
Last sector
verified?
Remove V
from RESET#
Yes
Yes
Yes
Yes
ID
No
Temporary Sector
Unprotect Mode
Set up
next sector
address
No
ID
Algorithm
Write reset
command
Figure 1. In-System Sector Protect/Unprotect Algorithms
11 Am29LV017B
Sector Unprotect
complete
21415C-4
PRELIMINARY
START
RESET# = V
(Note 1)
Perform Erase or
Program Operations
RESET# = V
Temporary Sector
Unprotect Completed
(Note 2)
Notes:
1. All protected sectors unprotected.
2. All previously protected sectors are protected once again.
ID
IH
21415C-5
against inadverten t writes (refer to Table 8 for com­mand definitions). In addition, the following hardwar e data protection mea sures prevent accidental erasure or programming, which might otherwise be caused by spurious system level signals during V
power-up
CC
and power-down transitions, or from system noise.
Low V
When V cept any write cycles. This protects data during V
Write Inhibit
CC
is less than V
CC
, the device does not ac-
LKO
CC
power-up and power-down. The command register and all internal program/erase circuits are disabled, and the device resets. Subsequent writes are ignored until V is greater than V
. The system must provide the
LKO
CC
proper signals to the control pins to prevent uninten­tional writes when V
is greater than V
CC
LKO
.

Write Pulse “Glitch” Protection

Noise pulses of less than 5 ns (typical) on OE#, CE# or WE# do not initiate a write cycle.

Logical Inhibit

Write cycles are inhibited by holding any one of OE#
, CE# = VIH or WE# = VIH. To initiate a writ e cy-
= V
IL
cle, CE# and WE# must be a logical zero while OE# is a logical one.
Figure 2. Temporary Sector Unprotect Operation

Hardware Data Protection

The command sequence requirement of unlock cycles for programming or erasing provides data protection
Power-Up Write Inhibit
If WE# = CE# = V
and OE# = VIH during powe r
IL
up, the device does not accept commands on the rising edge of WE#. The internal state machine is automatically reset to reading array data on power-up.
Am29LV017B 12
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