R
MX29LV160BT/BB
tive current specification for the write mode. The "AC
Characteristics" section contains timing specification
table and timing diagrams for write operations.
REQUIREMENTS FOR READING ARRAY
DATA
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.
STANDBY MODE
When using both pins of CE and RESET, the device
enter CMOS Standby with both pins held at Vcc ±0.3V.
If CE and RESET are held at VIH, 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 active current (ICC2) is required
even CE = "H" until the operation is completed.The de-
vice can be read with standard access time (tCE) from
either of these standby modes, before it is ready to read
data.
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 con-
tent 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.
OUTPUT DISABLE
WRITE COMMANDS/COMMAND SEQUENCES
With the OE input at a logic high level (VIH), output from
the devices are disabled.This will cause the output pins
to be in a high impedance state.
To program data to the device or erase sectors of
memory, the system must drive WE and CE to VIL, and
OE to VIH.
RESET OPERATION
An erase operation can erase one sector, multiple sec-
tors, or the entire device.Table 1 andTable 2 indicate the
address space that each sector occupies. A "sector ad-
dress" consists of the address bits required to uniquely
select a sector. The Writing specific address and data
commands or sequences into the command register ini-
tiates device operations.Table 5 defines the valid regis-
ter command sequences.Writing incorrect address and
data values or writing them in the improper sequence
resets the device to reading array data. Section has de-
tails on erasing a sector or the entire chip, or suspend-
ing/resuming the erase operation.
The RESET pin provides a hardware method of reset-
ting the device to reading array data.When the RESET
pin is driven low for at least a period of tRP, the device
immediately terminates any operation in progress,
tristates all output pins, and ignores all read/write com-
mands for the duration of the RESET pulse.The device
also resets the internal state machine to reading array
data. The operation that was interrupted should be re-
initiated once the device is ready to accept another com-
mand sequence, to ensure data integrity.
After the system writes the "read silicon-ID" and "sector
protect verify" command sequence, the device enters
the "read silicon-ID" and "sector protect verify" mode.
The system can then read "read silicon-ID" and "sector
protect verify" 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 "read
silicon-ID" and "sector protect verify" Mode and "read
silicon-ID" and "sector protect verify" Command Se-
quence section for more information.
Current is reduced for the duration of the RESET pulse.
When RESET is held at VSS±0.3V, the device draws
CMOS standby current (ICC4). If RESET is held at VIL
but not within VSS±0.3V, the standby current will be
greater.
The RESET pin may be tied to system reset circuitry. A
system reset would that also reset the Flash memory,
enabling the system to read the boot-up firmware from
the Flash memory.
ICC2 in the DC Characteristics table represents the ac-
If RESET is asserted during a program or erase opera-
P/N:PM1041
REV. 1.2, JUL. 01, 2004
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