MX29LV800C T/B
form.
To verify programming of the protection circuitry, the pro-
gramming equipment must forceVID 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. Other-
wise 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.
CHIP UNPROTECTED
The MX29LV800CT/B also features the chip unprotected
mode, so that all sectors are unprotected after chip un-
protected is completed to incorporate any changes in the
code. It is recommended to protect all sectors before
activating chip unprotected 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. Refer to chip unprotected algorithm and waveform
for the chip unprotected algorithm. The unprotection
mechanism begins on the falling edge of the WE# pulse
and is terminated on the rising edge.
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
unprotected algorithm is completed.
P/N:PM1183
REV. 1.4, APR. 24, 2006
21
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