AM29LV800DB120EC SPANSION [SPANSION], AM29LV800DB120EC Datasheet - Page 18
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AM29LV800DB120EC
Manufacturer Part Number
AM29LV800DB120EC
Description
8 Megabit (1 M x 8-Bit/512 K x 16-Bit) CMOS 3.0 Volt-only Boot Sector Flash Memory
Manufacturer
SPANSION [SPANSION]
Datasheet
1.AM29LV800DB120EC.pdf
(46 pages)
codes, and determine whether or not a sector is pro-
tected. Table 5 shows the address and data require-
ments. This method is an alternative to that shown in
Table 4, which is intended for PROM programmers
and requires V
The autoselect command sequence is initiated by writ-
ing two unlock cycles, followed by the autoselect com-
mand. The device then enters the autoselect mode,
and the system may read at any address any number
of times, without initiating another command se-
quence.
A read cycle at address XX00h retrieves the manufac-
turer code. A read cycle at address XX01h in word
mode (or 02h in byte mode) returns the device code. A
read cycle containing a sector address (SA) and the
address 02h in word mode (or 04h in byte mode) re-
turns 01h if that sector is protected, or 00h if it is un-
protected. Refer to Tables 2 and 3 for valid sector
addresses.
The system must write the reset command to exit the
autoselect mode and return to reading array data.
Word/Byte Program Command Sequence
The system may program the device by word or byte,
depending on the state of the BYTE# pin. Program-
ming is a four-bus-cycle operation. The program com-
mand sequence is initiated by writing two unlock write
cycles, followed by the program set-up command. The
program address and data are written next, which in
turn initiate the Embedded Program algorithm. The
system is not required to provide further controls or
timings. The device automatically provides internally
generated program pulses and verifies the pro-
grammed cell margin. Table 5 shows the address and
data requirements for the byte program command se-
quence.
When the Embedded Program algorithm is complete,
the device then returns to reading array data and ad-
dresses are no longer latched. The system can deter-
mine the status of the program operation by using
DQ7, DQ6, or RY/BY#. See “Write Operation Status”
for information on these status bits.
16
ID
on address bit A9.
D A T A
Am29LV800D
S H E E T
Any commands written to the device during the Em-
bedded Program Algorithm are ignored. Note that a
hardware reset immediately terminates the program-
ming operation. The program command sequence
should be reinitiated once the device has reset to
reading array data, to ensure data integrity.
Programming is allowed in any sequence and across
sector boundaries. A bit cannot be programmed
from a “0” back to a “1”. Attempting to do so may
halt the operation and set DQ5 to “1”, or cause the
Data# Polling algorithm to indicate the operation was
successful. However, a succeeding read will show that
the data is still “0”. Only erase operations can convert
a “0” to a “1”.
Unlock Bypass Command Sequence
The unlock bypass feature allows the system to pro-
gram bytes or words to the device faster than using the
standard program command sequence. The unlock
bypass command sequence is initiated by first writing
two unlock cycles. This is followed by a third write
cycle containing the unlock bypass command, 20h.
The device then enters the unlock bypass mode. A
two-cycle unlock bypass program command sequence
is all that is required to program in this mode. The first
cycle in this sequence contains the unlock bypass pro-
gram command, A0h; the second cycle contains the
program address and data. Additional data is pro-
grammed in the same manner. This mode dispenses
with the initial two unlock cycles required in the stan-
dard program command sequence, resulting in faster
total programming time. Table 5 shows the require-
ments for the command sequence.
During the unlock bypass mode, only the Unlock By-
pass Program and Unlock Bypass Reset commands
are valid. To exit the unlock bypass mode, the system
must issue the two-cycle unlock bypass reset com-
mand sequence. The first cycle must contain the data
90h; the second cycle the data 00h. Addresses are
don’t care for both cycles. The device then returns to
reading array data.
Figure 3 illustrates the algorithm for the program oper-
ation. See the
Characteristics” for parameters, and to Figure 17 for
timing diagrams.
Erase/Program Operations
Am29LV800D_00_A7 December 4, 2006
table in “AC