2 Am29DL642G Spetember 5, 2002
PRELIMINARY
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
fla sh mem ory devic es in a sin gle 63 -bal l Fo rtifi ed BG A
pac ka ge. Each Am 29 DL 64 0G i s 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. T he device is des igned t o be pr o-
grammed in-system with the standard system 3.0 volt
VCC supply. A 12.0 volt VPP is not required for p rogram 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-
gra mmed in stan dard EPR OM pro gr amme rs.
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 tw o dice i n the Am 29DL642G package. To the sys-
tem, this device will be the same as tw o independent
Am29DL640G on the same board. The only difference
is that they are now packaged together to reduce
board spac e.
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-
ter nally ge nerated and regu lated v oltage s are pro vided
for the progra m and erase oper ations.
Simul taneo us Read /Write Oper ations with
Zero Latency
The Simu ltaneou s Read/ Writ e archit ecture provide s si-
multaneous operati on by div i di ng the me mo ry sp ac e of
each Am29DL640G device into fou r 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.
During an Erase/Prog ram 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 pr ogram or erase i n one bank, the n immediate ly
and simu ltaneo usly read from the other ban k, with zero
latency. This releases the system from waiting for the
completion of program or erase operations.
Each Am29DL640G can be organized as both a top and
bottom boot sector configuration.
Am29DL642G Features
The S ecSi™ (Sec ured S ilicon) Se ctor is an extra 256
by te sec to r cap abl e of be in g per m an ently loc ked by AMD
or customers. The SecSi Indicator Bit (DQ7) is perma-
nently set to a 1 if the part is factory locked, and set to a
0 if customer l ocka ble. 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 stor e a sec ure, 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 Ma nagemen t Softw are) allows systems to
eas ily tak e adva nta ge o f the a dvan c ed arch i tecture of the
simultaneous read/write product line by allowing removal
of EEPROM devices. DMS will also allow the system
software to be simplified, as it will perform all functions
necessary 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-
cat ed in the syste m. This is an ad vant age compar ed to
systems where user-written s oftware must keep track of
the ol d da ta locati o n, statu s, l o gical to p hysical tr an slati on
of the data on to the Flas h memor y device (or memory d e-
vices), and more. Using DMS, user-written software does
not need to interf ace with the Flash memory directly. In-
stea d, t he user 's s o ftwar e acces se s the F las h me mo ry b y
calling one of only six functions. AMD provides this soft-
ware t o si mplify s ystem de sign an d softwar e int egration
efforts.
The de vice offers comple te comp atibility wi th 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 sim ilar t o reading from other Flash or
EPROM devices.
The host system can detect whether a program or erase
operation is complete by using the device status bits :
RY/BY# pin, DQ7 (D ata# Polling) and DQ6/DQ2 (toggl e
bits). After a program or erase cycle has been com-
plet ed, the device auto matically returns to the read mode.
The secto r e rase a rch it ec ture allows memory sectors to
be er ased and reprogrammed w ithout affecting the dat a
con ten ts of oth er sectors . T he de v ice is fu lly e ra sed w hen
shipped from the factory.
Ha rdware dat a prote ction measures include a low VCC
detec tor that auto matically inhi bits write operations dur-
ing power t ransitions. The har dware sector p rotection
feature disables both program and erase operations in
any comb inati on of the se ctors of me mory. This can b e
achieved in-system or via programming equipment.
The device offers two power-s aving features. When ad-
dresses have been stable for a specified amount of time,
the d evic e e nters the a utomati c sl eep m ode. Th e sy s-
tem can a lso pla ce the devi ce into t he standby mode.
Power consumption is greatly reduced in both modes.
Bank Megabits Sector Sizes
Bank 1 8 Mb Eight 4 Kword,
Fifteen 32 Kword
Bank 2 24 Mb Forty-eight 32 Kword
Bank 3 24 Mb Forty-eight 32 Kword
Bank 4 8 Mb Eight 4 Kword,
Fifteen 32 Kword