D A T A S H E E T
Step 1
Step 2
Step 3
40 ns
40 ns
40 ns
40 ns
40 ns
CLK
LBA#
BAA#
Data
Da
Da +1
Da +2
Da +3
70 ns
24 ns
24 ns
24 ns
OE#
Figure 4. Burst Mode Read with 25 MHz CLK, 70 ns t
, 24 ns t
Parameters
IACC
BACC
is intended for PROM programmers and requires V
on address bit A9.
Reset Command
Writing the reset command to the device resets the de-
vice to reading array data. Address bits are don’t care
for this command.
ID
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 sequence.
The reset command may be written between the se-
quence cycles in an erase command sequence before
erasing begins. This resets the device to reading array
data. Once erasure begins, however, the device ig-
nores reset commands until the operation is complete.
A read cycle at address 00h retrieves the manufacturer
code. A read cycle at address 01h returns the device
code. A read cycle containing a sector address (SA)
and the address 02h in word mode returns 0001h if that
sector is protected, or 0000h if it is unprotected. Refer
to Table 2 for valid sector addresses. A read cycle at
address 03h returns 0000h if the device is in asynchro-
nous mode, or 0001h if in synchronous (burst) mode.
The reset command may be written between the se-
quence cycles in a program command sequence be-
fore programming begins. This resets the device to
reading array data (also applies to programming in
Erase Suspend mode). Once programming begins,
however, the device ignores reset commands until the
operation is complete.
The system must write the reset command to exit the
autoselect mode and return to reading array data.
The reset command may be written between the se-
quence cycles in an autoselect command sequence.
Once in the autoselect mode, the reset command must
be written to return to reading array data (also applies
to autoselect during Erase Suspend).
Program Command Sequence
Programming is a four-bus-cycle operation. The pro-
gram command 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 al-
gorithm. The system is not required to provide further
controls or timings. The device automatically gener-
ates the program pulses and verifies the programmed
cell margin. Table 4 shows the address and data re-
quirements for the program command sequence.
If DQ5 goes high during a program or erase operation,
writing the reset command returns the device to read-
ing array data (also applies during Erase Suspend).
See “AC Characteristics” for parameters, and to Figure
17 for the timing diagram.
Autoselect Command Sequence
The autoselect command sequence allows the host
system to access the manufacturer and devices codes,
and determine whether or not a sector is protected.
Table 4 shows the address and data requirements. This
method is an alternative to that shown in Table 1, which
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 in-
formation on these status bits.
16
Am29BL802C
22371C7 November 3, 2006
SPANSION [ SPANSION ]
