MX29LV320AT/B
REQUIREMENTS FOR READING ARRAY
DATA
ACCELERATED PROGRAM OPERATION
The device offers accelerated program operations through
the WP/ACC function. If the system asserts VHH on ACC
pin, the device will provide the fast programming time to
user. This function is primarily intended to allow faster
manufacturing throughput during production. Removing
VHH from the WP/ACC pin returns the device to normal
operation. Note that the WP/ACC pin must not be at VHH
for operations other than accelerated programming, or
device damage may result.
To read array data from the outputs, the system must
drive the CE and OE pins toVIL.CE is the power control
and selects the device. OE is the output control and gates
array data to the output pins. WE should remain at VIH.
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 command is
necessary in this mode to obtain array data. Standard
microprocessor read cycles that assert valid address 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.
STANDBY MODE
MX29LV320AT/B can be set into Standby mode with two
different approaches. One is using both CE and RESET
pins and the other one is using RESET pin only.
When using both pins of CE and RESET, a CMOS
Standby mode is achieved with both pins held at Vcc ±
0.3V. Under this condition, the current consumed is less
than 0.2uA (typ.). If both of the CE and RESET are held
atVIH, but not within the range ofVCC ± 0.3V, the device
will still be in the standby mode, but the standby current
will be larger. During Auto Algorithm operation, Vcc ac-
tive current (ICC2) is required even CE = "H" until the
operation is completed.The device can be read with stan-
dard access time (tCE) from either of these standby
modes.
WRITE COMMANDS/COMMAND SEQUENCES
To program data to the device or erase sectors of memory
, the system must drive WE and CE to VIL, and OE to
VIH.
An erase operation can erase one sector, multiple sectors
, or the entire device.Table 1 indicates the address space
that each sector occupies. A "sector address" consists
of the address bits required to uniquely select a sector.
Writing specific address and data commands or
sequences into the command register initiates device
operations. Table 3 defines the valid register command
sequences.Writing incorrect address and data values or
writing them in the improper sequence resets the device
to reading array data. Section has details on erasing a
sector or the entire chip, or suspending/resuming the erase
operation.
When using only RESET, a CMOS standby mode is
achieved with RESET input held at Vss ± 0.3V, Under
this condition the current is consumed less than 1uA
(typ.). Once the RESET pin is taken high, the device is
back to active without recovery delay.
In the standby mode the outputs are in the high imped-
ance state, independent of the OE input.
After the system writes the Automatic Select command
sequence, the device enters the Automatic Select mode.
The system can then read Automatic Select codes from
the internal register (which is separate from the memory
array) on Q7-Q0. Standard read cycle timings apply in
this mode. Refer to the Automatic Select Mode and
Automatic Select Command Sequence section for more
information.
MX29LV320AT/B is capable to provide the Automatic
Standby Mode to restrain power consumption during read-
out of data. This mode can be used effectively with an
application requested low power consumption such as
handy terminals.
To active this mode, MX29LV320AT/B automatically
switch themselves to low power mode when
MX29LV320AT/B addresses remain stable during access
time of tACC+30ns. It is not necessary to control CE,
WE, and OE on the mode. Under the mode, the current
consumed is typically 0.2uA (CMOS level).
ICC2 in the DC Characteristics table represents the active
current specification for the write mode. The "AC
Characteristics" section contains timing specification
table and timing diagrams for write operations.
P/N:PM1008
REV. 1.1, MAY 28, 2004
11
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