MX29LV320MB Macronix International, MX29LV320MB Datasheet - Page 14

• Manufacturer Part Number: MX29LV320MB
• Description: 32M-BIT [4M x 8/2M x 16] SINGLE VOLTAGE 3V ONLY FLASH MEMORY
• Manufacturer: Macronix International

It is also possible to determine if the group 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 OPERATION
The MX29LV320MT/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 ac-
tivating 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 unprotect
mechanism begins on the falling edge of the WE# pulse
and is terminated on the rising edge.
MX29LV320MT/B also provides another method. Which
requires VID on the RESET# only. This method can be
implemented either in-system or via programming equip-
ment. This method uses standard microprocessor bus
cycle timing.
It is also possible to determine if the chip is unprotect 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 unprotect sector. It is
noted that all sectors are unprotected after the chip
unprotect algorithm is completed.
WRITE PROTECT (WP#)
The write protect function provides a hardware method to
protect boot sectors without using V
If the system asserts VIL on the WP# pin, the device
disables program and erase functions in the two "outer-
most" 8 Kbyte boot sectors independently of whether those
sectors were protected or unprotect using the method
described in Sector "Sector Group Protection and Chip
Unprotect". The two outermost 8 Kbyte boot sectors are
the two sectors containing the lowest addresses in a
bottom-boot-configured device, or the two sectors con-
taining the highest addresses in a top-boot-configured
device.
P/N:PM1129
ID
.
14
If the system asserts VIH on the WP# pin, the device
reverts to whether the two outermost 8K Byte boot sec-
tors were last set to be protected or unprotect. That is,
sector protection or unprotection for these two sectors
depends on whether they were last protected or unprotect
using the method described in "Sector/Sector Group Pro-
tection and Chip Unprotect".
Note that the WP# pin must not be left floating or uncon-
nected; inconsistent behavior of the device may result.
TEMPORARY SECTOR GROUP UNPROTECT
OPERATION
This feature allows temporary unprotect of previously pro-
tected sector to change data in-system. The Temporary
Sector Unprotect mode is activated by setting the RE-
SET# pin to VID(11.5V-12.5V). During this mode, for-
merly protected sectors can be programmed or erased
as unprotect sector. Once VID is remove from the RE-
SET# pin, all the previously protected sectors are pro-
tected again.
SILICON ID READ OPERATION
Flash memories are intended for use in applications where
the local CPU alters memory contents. As such, manu-
facturer and device codes must be accessible while the
device resides in the target system. PROM program-
mers typically access signature codes by raising A9 to a
high voltage. However, multiplexing high voltage onto
address lines is not generally desired system design prac-
tice.
MX29LV320MT/B provides hardware method to access
the silicon ID read operation. Which method requires VID
on A9 pin, VIL on CE#, OE#, A6, and A1 pins. Which
apply VIL on A0 pin, the device will output MXIC's manu-
facture code.. Which apply VIH on A0 pin, the device will
output MX29LV320MT/B device code.
VERIFY SECTOR GROUP PROTECT STATUS
OPERATION
MX29LV320MT/B provides hardware method for sector
group protect status verify. Which method requires VID
on A9 pin, VIH on WE# and A1 pins, VIL on CE#, OE#,
A6, and A0 pins, and sector address on A16 to A20 pins.
MX29LV320MT/B
REV. 1.1 , JUL. 14, 2005
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