MX26LV004T Macronix, MX26LV004T Datasheet - Page 16

• Manufacturer Part Number: MX26LV004T
• Description: (MX26LV004T/B) 4M-Bit CMOS Single Voltage Flash Memory
• Manufacturer: Macronix

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 MX26LV004T/B 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 incorporates
several features to prevent inadvertent write cycles re-
sulting 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:PM1099
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 MX26LV004T/B powers up in the Read only mode.
In addition, the memory contents may only be altered
after successful completion of the predefined command
sequences.
ER SUPPLY DECOUPLING
MX26LV004T/B
REV. 0.02, JUL. 12, 2004