AM29LV640MB110REI Spansion Inc., AM29LV640MB110REI Datasheet - Page 14

• Manufacturer Part Number: AM29LV640MB110REI
• Manufacturer: Spansion Inc.

Specifications of AM29LV640MB110REI

• Cell Type: NOR
• Density: 64Mb
• Access Time (max): 110ns
• Interface Type: Parallel
• Boot Type: Bottom
• Address Bus: 23/22Bit
• Operating Supply Voltage (typ): 3.3V
• Operating Temp Range: -40C to 85C
• Package Type: TSOP
• Program/erase Volt (typ): 3 to 3.6V
• Sync/async: Asynchronous
• Operating Temperature Classification: Industrial
• Operating Supply Voltage (min): 3V
• Operating Supply Voltage (max): 3.6V
• Word Size: 8/16Bit
• Number Of Words: 8M/4M
• Supply Current: 20mA
• Mounting: Surface Mount
• Pin Count: 48
• Lead Free Status / Rohs Status: Not Compliant

The internal state machine is set for reading array 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 com-
mand is necessary in this mode to obtain array data.
Standard microprocessor read cycles that assert valid
addresses on the device address inputs produce valid
data on the device data outputs. The device remains
enabled for read access until the command register
contents are altered.
See See
formation. See the table,
page 45
the timing diagram. Refer to the DC Characteristics
table for the active current specification on reading
array data.
Page Mode Read
The device is capable of fast page mode read and is
compatible with the page mode Mask ROM read oper-
ation. This mode provides faster read access speed
for random locations within a page. The page size of
the device is 4 words/8 bytes. The appropriate page is
selected by the higher address bits A(max)–A2. Ad-
dress bits A1–A0 in word mode (A1–A-1 in byte mode)
determine the specific word within a page. This is an
asynchronous operation; the microprocessor supplies
the specific word location.
The random or initial page access is equal to t
t
the locations specified by the microprocessor falls
within that page) is equivalent to t
deasserted and reasserted for a subsequent access,
the access time is t
cesses are obtained by keeping the “read-page ad-
dresses” constant and changing the “intra-read page”
addresses.
Writing Commands/Command Sequences
To write a command or command sequence (which in-
cludes 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 facili-
tate faster programming. Once the device enters the
Unlock Bypass mode, only two write cycles are re-
quired to program a word or byte, instead of four. The
Word/Byte Program Command Sequence on page 29
has details on programming data to the device using
both standard and Unlock Bypass command se-
quences.
An erase operation can erase one sector, multiple sec-
tors, or the entire device.
the address space that each sector occupies.
12
CE
and subsequent page read accesses (as long as
for timing specifications and to
IL
Reading Array Data on page 27
, and OE# to V
ACC
IH
or t
Table 2
.
Read-Only Operations on
CE
. Fast page mode ac-
and
PACC
Table 3
. When CE# is
Figure 14
for more in-
D A T A
indicates
Am29LV640MT/B
ACC
for
or
S H E E T
Refer to the DC Characteristics table for the active
current specification for the write mode.
istics on page 45
and timing diagrams for write operations.
Write Buffer
Write Buffer Programming allows the system to write a
maximum of 16 words/32 bytes in one programming
operation. This results in faster effective programming
time than the standard programming algorithms. See
Write Buffer on page 12
Accelerated Program Operation
The device offers accelerated program operations
through the ACC function. This is one of two functions
provided by the WP#/ACC pin. This function is prima-
rily intended to allow faster manufacturing throughput
at the factory.
If the system asserts V
matically enters the aforementioned Unlock Bypass
mode, temporarily unprotects any protected sectors,
and uses the higher voltage on the pin to reduce the
time required for program operations. The system
would use a two-cycle program command sequence
as required by the Unlock Bypass mode. Removing
V
mal operation. Note that the WP#/ACC pin must not be
at V
ming, or device damage can result. In addition, no ex-
ternal pullup is necessary since the WP#/ACC pin has
internal pullup to V
Autoselect Functions
If the system writes the autoselect command se-
quence, the device enters the autoselect mode. The
system can then read autoselect codes from the inter-
nal register (which is separate from the memory array)
on DQ7–DQ0. Standard read cycle timings apply in
this mode. See
toselect Command Sequence on page 28
formation.
Standby Mode
When the system is not reading or writing to the de-
vice, it can place the device in the standby mode. In
this mode, current consumption is greatly reduced,
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# pins are both held at V
(Note that this is a more restricted voltage range than
V
V
standby current is greater. The device requires stan-
dard access time (t
HH
IH
CC
.) If CE# and RESET# are held at V
HH
from the WP#/ACC pin returns the device to nor-
± 0.3 V, the device is in the standby mode, but the
for operations other than accelerated program-
Autoselect Mode on page 19
contains timing specification tables
CC
CE
.
) for read access when the de-
HH
for more information.
on this pin, the device auto-
26190C8 February 1, 2007
IH
AC Character-
, but not within
for more in-
CC
and
± 0.3 V.
Au-