ADVANCE INFORMATION
Am29LV020B
2 Megabit (256 K x 8-Bit)
CMOS 3.0 Volt-only, Uniform Sector 32-Pin Flash Memory
DISTINCTIVE CHARACTERISTICS
s
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
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Manufactured on 0.35 µm process technology
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High performance
— Full voltage range: access times as fast as 70 ns
— Regulated voltage range: access times as fast
as 55 ns
s
Ultra low power consumption
— Automatic sleep mode: 1 µA (typical values at
5 MHz)
— Standby mode: 1 µA
— Read mode: 7 mA
— Program/erase mode: 15 mA
s
Flexible sector architecture
— Four 64 Kbyte sectors
— Any combination of sectors can be erased;
supports full chip erase
— Sector Protection features:
Hardware method of locking a sector to prevent
any program or erase operations within that
sector
Sectors can be locked via programming
equipment
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Unlock Bypass Program Command
— Reduces overall programming time when
issuing multiple program command sequences
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Embedded Algorithms
— Embedded Erase algorithms automatically
preprogram and erase the entire chip or any
combination of designated sectors
— Embedded Program algorithms automatically
writes and verifies data at specified addresses
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Minimum 1,000,000 write/erase cycles
guaranteed
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Package option
— 32-pin PLCC
— 32-pin TSOP
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Compatibility with JEDEC standards
— Pinout and software compatible with single-
power supply Flash
— Superior inadvertent write protection
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Data# Polling and toggle bits
— Provides a software method of detecting
program or erase cycle completion
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Erase Suspend/Resume
— Supports reading data from or programming
data to a sector not being erased
This document contains information on a product under development at Advanced Micro Devices. The information
is intended to help you evaluate this product. AMD reserves the right to change or discontinue work on this proposed
product without notice. 2/9/98
Publication#
21351
Rev:
A
Amendment/+1
Issue Date:
February 1998
Refer to AMD’s Website (www.amd.com) for the latest information.
A D V A N C E
I N F O R M A T I O N
GENERAL DESCRIPTION
The Am29LV020B is a single power supply, 2 Mbit, 3.0
Volt-only Flash memory device organized as 262,144
bytes. The data appears on DQ0-DQ7. The device is
available in 32-pin PLCC and 32-pin TSOP packages.
All read, erase, and program operations are accom-
plished using only a single power supply. The device
can also be programmed in standard EPROM pro-
grammers.
The device offers access times of 55, 70, 90, and 120
ns allowing high speed microprocessors to operate
without wait states. To eliminate bus contention, the
device has separate control pins—chip enable (CE#),
write enable (WE#), and output enable (OE#)—to
control normal read and write operations.
The device requires only a
single power supply
(2.7
V–3.6 V) 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.
Com-
mands are written to the command register using
standard microprocessor write timings. Register con-
tents 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 auto-
matically times the program pulse widths and verifies
proper cell margin. The
Unlock Bypass
mode facili-
tates faster programming times by requiring only two
write cycles to program data instead of four.
Device erasure occurs by executing the erase com-
mand sequence. This initiates the
Embedded Erase
algorithm—an internal algorithm that automatically
preprograms the array (if it is not already programmed)
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 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 architecture
allows memory sectors
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
V
CC
detector that automatically inhibits write opera-
tions during power transitions. The
hardware sector
protection
feature disables both program and erase
operations in any combination of the sectors of mem-
ory. This is achieved 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 device offers two power-saving features. When ad-
dresses have been stable for a specified amount of
time, the device enters the
automatic sleep mode.
The system can also place the device 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 effective-
ness. The device electrically erases all bits within a
sector simultaneously via Fowler-Nordheim tun-
neling. The data is programmed using hot electron
injection.
2
Am29LV020B
2/9/98
实时操作系统RTOS
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