P R E L I M I N A R Y
GENERAL DESCRIPTION
The Am29DL642G is a 128 Mbit, 3.0 Volt (2.7 V to 3.6 V)
that combines two Am29DL640G single power supply
flash memory devices in a single 63-ball Fortified BGA
package. Each Am29DL640G is a 64 Mbit, 3.0 Volt (2.7 V
to 3.6 V) device organized as 4,194,304 words. Data ap-
pears on DQ15-DQ0. The device is designed to be pro-
grammed in-system with the standard system 3.0 volt
VCC supply. A 12.0 volt VPP is not required for program or
erase operations. The Am29DL642G is equipped with
two CE# inputs for flexible selection between the two in-
ternal 64 Mb devices. The device can also be pro-
grammed in standard EPROM programmers.
nently set to a 1 if the part is factory locked, and set to a
0 if customer lockable. This way, customer lockable
parts can never be used to replace a factory locked part.
Factory locked parts provide several options. The SecSi
Sector may store a secure, random 16 byte ESN (Elec-
tronic Serial Number), customer code (programmed
through AMD’s ExpressFlash service), or both. Customer
Lockable parts may utilize the SecSi Sector as bonus
space, reading and writing like any other flash sector, or
may permanently lock their own code there.
DMS (Data Management Software) allows systems to
easily take advantage of the advanced architecture of the
simultaneous read/write product line by allowing removal
of EEPROM devices. DMS will also allow the system soft-
ware to be simplified, as it will perform all functions nec-
essary to modify data in file structures, as opposed to
single-byte modifications. To write or update a particular
piece of data (a phone number or configuration data, for
example), the user only needs to state which piece of
data is to be updated, and where the updated data is lo-
cated in the system. This is an advantage compared to
systems where user-written software must keep track of
the old data location, status, logical to physical translation
of the data onto the Flash memory device (or memory
devices), and more. Using DMS, user-written software
does not need to interface with the Flash memory di-
rectly. Instead, the user's software accesses the Flash
memory by calling one of only six functions. AMD pro-
vides this software to simplify system design and soft-
ware integration efforts.
The Am29DL642G offers an access time of 70 or 90 ns.
To eliminate bus contention the Am29DL642G device has
two separate chip enables (CE# and CE2#). Each chip
enable (CE# or CE2#) is connected to only one of the two
dice in the Am29DL642G package. To the system, this
device will be the same as two independent
Am29DL640G on the same board. The only difference
is that they are now packaged together to reduce
board space.
Each device requires only a single 3.0 Volt power sup-
ply (2.7 V to 3.6 V) for both read and write functions. In-
ternally generated and regulated voltages are provided
for the program and erase operations.
Simultaneous Read/Write Operations with
Zero Latency
The Simultaneous Read/Write architecture provides si-
multaneous operation by dividing the memory space of
each Am29DL640G device into four banks, two 8 Mb
banks with small and large sectors, and two 24 Mb banks
of large sectors. Sector addresses are fixed, system soft-
ware can be used to form user-defined bank groups.
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 timings. Reading data out
of the device is similar to reading from other Flash or
EPROM devices.
During an Erase/Program operation, any of the three
non-busy banks may be read from. Note that only two
banks can operate simultaneously. The device can im-
prove 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.
The host system can detect whether a program or erase
operation is complete by using the device status bits:
RY/BY# pin, DQ7 (Data# Polling) and DQ6/DQ2 (toggle
bits). After a program or erase cycle has been completed,
the device automatically returns to the read mode.
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.
Each Am29DL640G can be organized as both a top and
bottom boot sector configuration.
Bank
Megabits
Sector Sizes
Eight 4 Kword,
Fifteen 32 Kword
Hardware data protection measures include a low VCC
detector that automatically inhibits write operations dur-
ing 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.
Bank 1
8 Mb
Bank 2
Bank 3
24 Mb
24 Mb
Forty-eight 32 Kword
Forty-eight 32 Kword
Eight 4 Kword,
Fifteen 32 Kword
Bank 4
8 Mb
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 sys-
tem can also place the device into the standby mode.
Power consumption is greatly reduced in both modes.
Am29DL642G Features
The SecSi™ (Secured Silicon) Sector is an extra 256
byte sector capable of being permanently locked by AMD
or customers. The SecSi Indicator Bit (DQ7) is perma-
2
Am29DL642G
June 10, 2005
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