This product has been retired and is not recommended for designs. For new and current designs, S29AL004D supersedes Am29DL400B and is the factory-recommended migration path.
Please refer to the S29AL004D datasheet for specifications and ordering information. Availability of this document is retained for reference and historical purposes only.
DISTINCTIVE CHARACTERISTICS
■
Simultaneous Read/Write operations
— Host system can program or erase in one bank,
then immediately and simultaneously read
from the other bank
— Zero latency between read and write
operations
— Read-while-erase
— Read-while-program
— Sectors can be locked in-system or via
programming equipment
— Temporary Sector Unprotect feature allows
code changes in previously locked sectors
■
Top or bottom boot block configurations
available
■
Embedded Algorithms
— Embedded Erase algorithm automatically
pre-programs and erases sectors or entire chip
— Embedded Program algorithm automatically
programs and verifies data at specified address
■
Single power supply operation
— 2.7 to 3.6 volt read and write operations for
battery-powered applications
■
Manufactured on 0.32 µm process
technology
■
High performance
— Access times as fast as 70 ns
■
Minimum 1 million program/erase cycles
guaranteed per sector
■
20-year data retention at 125° C
— Reliable operation for the life of the system
■
Low current consumption (typical
values at 5 MHz)
— 7 mA active read current
— 21 mA active read-while-program or read-
while-erase current
— 17 mA active program-while-erase-suspended
current
— 200 nA in standby mode
— 200 nA in automatic sleep mode
— Standard t
CE
chip enable access time applies to
transition from automatic sleep mode to active
mode
■
Package options
— 44-pin SO
— 48-pin TSOP
■
Compatible with JEDEC standards
— Pinout and software compatible with
single-power-supply flash standard
— Superior inadvertent write protection
■
Data# Polling and Toggle Bits
— Provides a software method of detecting
program or erase cycle completion
■
Flexible sector architecture
— Two 16 Kword, two 8 Kword, four 4 Kword, and
six 32 Kword sectors in word mode
— Two 32 Kbyte, two 16 Kbyte, four 8 Kbyte, and
six 64 Kbyte sectors in byte mode
— Any combination of sectors can be erased
— Supports full chip erase
■
Ready/Busy# output (RY/BY#)
— Hardware method for detecting program or
erase cycle completion
■
Erase Suspend/Erase Resume
— Suspends or resumes erasing sectors to allow
reading and programming in other sectors
— No need to suspend if sector is in the other
bank
■
Unlock Bypass Program Command
— Reduces overall programming time when
issuing multiple program command sequences
■
Hardware reset pin (RESET#)
— Hardware method of resetting the device to
reading array data
■
Sector protection
— Hardware method of locking a sector to
prevent any program or erase operation within
that sector
This Data Sheet states AMD’s current technical specifications regarding the Products described herein. This Data Sheet may
be revised by subsequent versions or modifications due to changes in technical specifications.
Publication#
21606
Rev:
E
Amendment/+4
Issue Date:
June 7, 2005
GENERAL DESCRIPTION
The Am29DL400B is an 4 Mbit, 3.0 volt-only flash
memory device, organized as 262,144 words or
524,288 bytes. The device is offered in 44-pin SO
and 48-pin TSOP packages. The word-wide (x16)
data appears on DQ0–DQ15; the byte-wide (x8)
data appears on DQ0–DQ7. This device requires only
a single 3.0 volt V
CC
supply to perform read, pro-
gram, and erase operations. A standard EPROM
programmer can also be used to program and erase
the device.
The standard device offers access times of 70, 80,
90, and 120 ns, allowing high-speed microprocessors
to operate without wait states. Standard control
pins—chip enable (CE#), write enable (WE#), and
output enable (OE#)—control read and write opera-
tions, and avoid bus contention issues.
The device requires only a
single 3.0 volt power
supply
for both read and write functions. Internally
generated and regulated voltages are provided for
the program and erase operations.
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 pro-
grammed) 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 automatically re-
turns to reading array data.
The
sector erase architecture
allows memory sec-
tors to be erased and reprogrammed wi thout
affecting the data contents of other sectors. The de-
vice 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 sec-
tors 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 within that
bank that is not selected for erasure. True back-
ground erase can thus be achieved. There is no need
to suspend the erase operation if the read data is in
the other bank.
The
hardware RESET# pin
terminates any opera-
tion in progress and resets the internal state
machine to reading array data. The RESET# pin may
be tied to the system reset circuitry. A system reset
would thus also reset the device to reading array
data, 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 mode.
The system can also place the device into the
standby mode.
Power consumption is greatly re-
duced in both these modes.
AMD’s Flash technology combines years of Flash
memory manufacturing experience to produce the
hi ghe st l evels of qua lity, rel iabi lity, and cost
effectiveness. The device electrically erases all bits
within a sector simultaneously via Fowler-Nordheim
tunneling. The bytes are programmed one byte or
word at a time using hot electron injection.
Simultaneous Read/Write Operations with
Zero Latency
The Simultaneous Read/Write architecture provides
simultaneous operation
by dividing the memory
space into two banks. Bank 1 contains boot/parame-
ter sectors, and Bank 2 consists of larger, code
sectors of uniform size. The device can improve
overall system performance by allowing a host sys-
tem to program or erase in one bank, then
immediately and simultaneously read from the other
bank, with
zero latency.
This releases the system
from waiting for the completion of program or erase
operations.
Am29DL400B Features
The device offers complete compatibility with the
JEDEC single-power-supply Flash command set
standard.
Commands are written to the command
register using standard microprocessor write tim-
ings. Register contents serve as input to an internal
state machine that controls the erase and program-
ming 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 pro-
g ra m c o m m a n d s e q u e n c e . T h i s i n i t i a t e s t h e
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