MX26LV160AT Macronix International, MX26LV160AT Datasheet - Page 17

• Manufacturer Part Number: MX26LV160AT
• Description: 16M-BIT [2Mx8/1Mx16] CMOS SINGLE VOLTAGE 3V ONLY BOOT SECTOR HIGH SPEED eLiteFlashTM MEMORY
• Manufacturer: Macronix International

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Q3
Sector Erase Timer
After the completion of the initial sector erase command
sequence, the sector erase time-out will begin. Q3 will
remain low until the time-out is complete. Data# Polling
and Toggle Bit are valid after the initial sector erase com-
mand sequence.
If Data# Polling or the Toggle Bit indicates the device
has been written with a valid erase command, Q3 may
be used to determine if the sector erase timer window is
still open. If Q3 is high ("1") the internally controlled
erase cycle has begun; attempts to write subsequent
commands to the device will be ignored until the erase
operation is completed as indicated by Data# Polling or
Toggle Bit. If Q3 is low ("0"), the device will accept
additional sector erase commands. To insure the com-
mand has been accepted, the system software should
check the status of Q3 prior to and following each sub-
sequent sector erase command. If Q3 were high on the
second status check, the command may not have been
accepted.
DATA PROTECTION
The MX26LV160AT/AB is designed to offer protection
against accidental erasure or programming caused by
spurious system level signals that may exist during power
transition. During power up the device automatically re-
sets the state machine in the Read mode. In addition,
with its control register architecture, alteration of the
memory contents only occurs after successful comple-
tion of specific command sequences. The device also
incorporates several features to prevent inadvertent write
cycles resulting from VCC power-up and power-down tran-
sition or system noise.
WRITE PULSE "GLITCH" PROTECTION
Noise pulses of less than 5ns(typical) on CE# or WE#
will not initiate a write cycle.
LOGICAL INHIBIT
Writing is inhibited by holding any one of OE# = VIL,
CE# = VIH or WE# = VIH. To initiate a write cycle CE#
and WE# must be a logical zero while OE# is a logical
one.
P/N:PM1123
MX26LV160AT/AB
17
POWER SUPPLY DECOUPLING
In order to reduce power switching effect, each device
should have a 0.1uF ceramic capacitor connected be-
tween its VCC and GND.
POWER-UP SEQUENCE
The MX26LV160AT/AB powers up in the Read only mode.
In addition, the memory contents may only be altered
after successful completion of the predefined command
sequences.
TEMPORARY SECTOR UNPROTECT
This feature allows temporary unprotection of previously
protected sector to change data in-system. The Tempo-
rary Sector Unprotect mode is activated by setting the
RESET# pin to VID (11.5V-12.5V). During this mode,
formerly protected sectors can be programmed or erased
as un-protected sector. Once VID is remove from the
RESET# pin. All the previously protected sectors are pro-
tected again.
SECTOR PROTECTION
The MX29LV160AT/AB features hardware sector protec-
tion. This feature will disable both program and erase
operations for these sectors protected. To activate this
mode, the programming equipment must force VID on
address pin A9 and OE# (suggest VID = 12V). Program-
ming of the protection circuitry begins on the falling edge
of the WE# pulse and is terminated on the rising edge.
Please refer to sector protect algorithm and waveform.
To verify programming of the protection circuitry, the pro-
gramming equipment must force VID on address pin A9
( with CE# and OE# at VIL and WE# at VIH). When
A1=VIH, A0=VIL, A6=VIL, it will produce a logical "1"
code at device output Q0 for a protected sector. Other-
wise the device will produce 00H for the unprotected sec-
tor. In this mode, the addresses, except for A1, are don't
care. Address locations with A1 = VIL are reserved to
read manufacturer and device codes. (Read Silicon ID)
It is also possible to determine if the sector is protected
in the system by writing a Read Silicon ID command.
Performing a read operation with A1=VIH, it will produce
a logical "1" at Q0 for the protected sector.
REV. 1.1, NOV. 18, 2004