MX29LV065B ETC1 [List of Unclassifed Manufacturers], MX29LV065B Datasheet - Page 16

• Manufacturer Part Number: MX29LV065B
• Description: 64M-BIT [8M x 8] CMOS EQUAL SECTOR FLASH MEMORY
• Manufacturer: ETC1 [List of Unclassifed Manufacturers]

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 MX29LV081B is designed to offer protection against
accidental erasure or programming caused by spurious
system level signals that may exist during power transi-
tion. During power up the device automatically resets
the state machine in the Read mode. In addition, with
its control register architecture, alteration of the memory
contents only occurs after successful completion of spe-
cific command sequences. The device also incorpo-
rates several features to prevent inadvertent write cycles
resulting from VCC power-up and power-down transition
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:PM1115
16
POW
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 MX29LV081B powers up in the Read only mode. In
addition, the memory contents may only be altered after
successful completion of the predefined command se-
quences.
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, for-
merly 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 MX29LV081B features hardware sector protection.
This feature will disable both program and erase opera-
tions for these sectors protected. To activate this mode,
the programming equipment must force VID on address
pin A9 and OE (suggest VID = 12V). Programming 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. Otherwise the
device will produce 00H for the unprotected sector. 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.
ER SUPPLY DECOUPLING
MX29LV081B
REV. 1.1, DEC. 20, 2004