MX29F100TTC-70 View Datasheet(PDF) - Macronix International
Part Name
Description
MFG CO.
'MX29F100TTC-70' PDF : 47 Pages View PDF
MX29F100T/B
DATA PROTECTION
The MX29F100T/B 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 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 specific
command sequences. The device also incorporates
several features to prevent inadvertent write cycles
resulting from VCC power-up and power-down transition
or system noise.
TEMPORARY SECTOR UNPROTECT
This feature allows temporary unprotection of previously
protected sector to change data in-system. The Temporary
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 protected
again.
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 inhibite 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 SUPPLY DECOUPLING
In order to reduced power switching effect, each device
should have a 0.1uF ceramic capacitor connected between
its VCC and GND.
SECTOR PROTECTION WITH 12V SYSTEM
The MX29F100T/B features hardware sector protection.
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 control pin OE, (suggest VID = 12V) A6 = VIL and
CE = VIL.(see Table 2) 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
programming equipment must force VID on address pin
A9 ( with CE and OE at VIL and WE at VIH. When A1=1,
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
address,except for A1, are in "don't care" state. 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.
CHIP UNPROTECT WITH 12V SYSTEM
The MX29F100T/B also features the chip unprotect mode,
so that all sectors are unprotected after chip unprotect is
completed to incorporate any changes in the code. It is
recommended to protect all sectors before activating chip
unprotect mode.
To activate this mode, the programming equipment must
force VID on control pin OE and address pin A9. The CE
pins must be set at VIL. Pins A6 must be set to VIH.(see
Table 2) Refer to chip unprotect algorithm and waveform
for the chip unprotect algorithm. The unprotection
mechanism begins on the falling edge of the WE pulse
and is terminated on the rising.
It is also possible to determine if the chip is unprotected
in the system by writing the Read Silicon ID command.
Performing a read operation with A1=VIH, it will produce
00H at data outputs(Q0-Q7) for an unprotected sector. It
is noted that all sectors are unprotected after the chip
unprotect algorithm is completed.
P/N:PM0548
REV. 1.2, NOV. 12, 2001
14
Share Link: 
