D A T A S H E E T
the sector address. The device ID is read in three
cycles.
from “0” back to a “1.” Attempting to do so may
cause that bank to set DQ5 = 1, or cause the DQ7 and
DQ6 status bit to indicate the operation was suc-
cessful. However, a succeeding read will show that the
data is still “0.” Only erase operations can convert a “0”
to a “1.”
Description
Address
(BA) + 00h
(BA) + 01h
(BA) + 0Eh
(BA) + 0Fh
Read Data
0001h
Manufacturer ID
Device ID, Word 1
Device ID, Word 2
Device ID, Word 3
227Eh
Unlock Bypass Command Sequence
2202h
The unlock bypass feature allows the system to prima-
rily program to a bank 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. That
bank 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 program
command, A0h; the second cycle contains the program
address and data. Additional data is programmed in
the same manner. This mode dispenses with the initial
two unlock cycles required in the standard program
command sequence, resulting in faster total program-
ming time. Table 10 shows the requirements for the
unlock bypass command sequences.
2200h
Sector Block
Lock/Unlock
0001 (locked),
0000 (unlocked)
(SA) + 02h
(BA) + 03h
Handshaking
43h
The system must write the reset command to return to
the read mode (or erase-suspend-read mode if the
bank was previously in Erase Suspend).
Program Command Sequence
Programming is a four-bus-cycle operation. The
program 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
algorithm. The system is not required to provide further
controls or timings. The device automatically provides
internally generated program pulses and verifies the
programmed cell margin. Table 10 shows the address
and data requirements for the program command
sequence.
During the unlock bypass mode, only the Unlock
Bypass Program and Unlock Bypass Reset commands
are valid. To exit the unlock bypass mode, the system
must issue the two-cycle unlock bypass reset
command sequence. The first cycle must contain the
bank address and the data 90h. The second cycle
need only contain the data 00h. The bank then returns
to the read mode.
When the Embedded Program algorithm is complete,
that bank then returns to the read mode and addresses
are no longer latched. The system can determine the
status of the program operation by monitoring DQ7 or
DQ6/DQ2. Refer to the Write Operation Status section
for information on these status bits.
The device offers accelerated program operations
through the V input. When the system asserts V
PP
PP
on this input, the device automatically enters the
Unlock Bypass mode. The system may then write the
two-cycle Unlock Bypass program command
sequence. The device uses the higher voltage on the
Any commands written to the device during the
Embedded Program Algorithm are ignored. Note that a
hardware reset immediately terminates the program
operation. The program command sequence should be
reinitiated once that bank has returned to the read
mode, to ensure data integrity.
V
input to accelerate the operation.
PP
Figure 1 illustrates the algorithm for the program oper-
ation. Refer to the Erase/Program Operations table in
the AC Characteristics section for parameters, and
Figure 13 for timing diagrams.
Programming is allowed in any sequence and across
sector boundaries. A bit cannot be programmed
22
Am29BDS643G
25692A2 May 8, 2006
SPANSION [ SPANSION ]
