en29lv040-45rtip Eon Silicon Solution Inc., en29lv040-45rtip Datasheet - Page 8

• Manufacturer Part Number: en29lv040-45rtip
• Description: 4 Megabit 512k X 8-bit Uniform Sector Cmos 3.0 Volt-only Flash Memory
• Manufacturer: Eon Silicon Solution Inc.

EN29LV040
Hardware Data Protection
The command sequence requirement of unlock cycles for programming or erasing provides data
protection against inadvertent writes as seen in the Command Definitions table. Additionally, the
following hardware data protection measures prevent accidental erasure or programming, which
might otherwise be caused by false system level signals during Vcc power up and power down
transitions, or from system noise.
Low V
Write Inhibit
CC
When Vcc is less than V
, the device does not accept any write cycles. This protects data during
LKO
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 V
. The
LKO
system must provide the proper signals to the control pins to prevent unintentional writes when Vcc
is greater than V
.
LKO
Write Pulse “Glitch” protection
Noise pulses of less than 5 ns (typical) on OE , CE or
do not initiate a write cycle.
W E
Logical Inhibit
Write cycles are inhibited by holding any one of OE = VIL, CE = VIH, or
= VIH. To initiate a
W E
write cycle, CE and
must be a logical zero while OE is a logical one. If CE ,
, and OE are
W E
W E
all logical zero (not recommended usage), it will be considered a read.
Power-up Write Inhibit
During power-up, the device automatically resets to READ mode and locks out write cycles. Even
with CE = V
, W E = V
and OE = V
, the device will not accept commands on the rising edge of
IL
IL
IH
.
W E
This Data Sheet may be revised by subsequent versions
8
©2003 Eon Silicon Solution, Inc., www.essi.com.tw
or modifications due to changes in technical specifications.
Rev. D, Issue Date: 2004/03/31