MX29LV065 Macronix, MX29LV065 Datasheet - Page 17

• Manufacturer Part Number: MX29LV065
• Description: 64M-Bit CMOS Flash Memory
• Manufacturer: Macronix

LOW VCC WRITE INHIBIT
When VCC is less than VLKO the device does not ac-
cept any write cycles. This protects data during VCC
power-up and power-down. The command register and
all internal program/erase circuits are disabled, and the
device resets. Subsequent writes are ignored until VCC
is greater than VLKO. The system must provide the proper
signals to the control pins to prevent unintentional write
when VCC is greater than VLKO.
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.
POWER-UP SEQUENCE
The MX29LV065 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.
POWER-UP WRITE INHIBIT
In order to reduce power switching effect, each device
should have a 0.1uF ceramic capacitor connected be-
tween its VCC and GND.
POWER SUPPLY DE COUPLING
In order to reduce power switching effect, each device
should have a 0.1uF ceramic capacitor connected be-
tween its VCC and GND.
P/N:PM0893
17
FACTORY LOCKED:Secured Silicon Sector
Programmed and Protected At the Factory
In device with an ESN, the Secured Silicon Sector is
protected when the device is shipped from the factory.
The Secured Silicon Sector cannot be modified in any
way. A factory locked device has an 16-byte random ESN
at address 000000h-00000Fh.
CUSTOMER LOCKABLE:Secured Silicon
Sector NOT Programmed or Protected At the
Factory
As an alternative to the factory-locked version, the device
may be ordered such that the customer may program
and protect the 256-byte Secured Silicon Sector.
Programming and protecting the Secured Silicon Sector
must be used with caution since, once protected, there
is no procedure available for unprotected the Secured
Silicon Sector area and none of the bits in the Secured
Silicon Sector memory space can be modified in any
way.
The Secured Silicon Sector area can be protected using
one of the following procedures:
Write the three-cycle Enter Secured Silicon Sector Region
command sequence, and then follow the in-system
sector protect algorithm as shown in Figure 2, except
that RESET may be at either VIH or VID. This allows in-
system protection of the Secured Silicon Sector without
raising any device pin to a high voltage. Note that method
is only applicable to the Secured Silicon Sector.
Write the three-cycle Enter Secured Silicon Sector Region
command sequence, and then alternate method of sector
protection described in the :Sector Group Protection and
Unprotected" section.
Once the Secured Silicon Sector is programmed, locked
and verified, the system must write the Exit Secured
Silicon Sector Region command sequence to return to
reading and writing the remainder of the array.
MX29LV065
REV. 0.4, JUL. 22, 2003