AM29PL320D SPANSION [SPANSION], AM29PL320D Datasheet - Page 22

• Manufacturer Part Number: AM29PL320D
• Description: 32 Megabit (2 M x 16-Bit/1 M x 32-Bit) CMOS 3.0 Volt-only High Performance Page Mode Flash Memory
• Manufacturer: SPANSION [SPANSION]

Erase Suspend mode, the system may once again
read array data with the same exception. See “Erase
Suspend/Erase Resume Commands” for more infor-
mation on this mode.
The system must issue the reset command to re-en-
able the device for reading array data if DQ5 goes
high, or while in the autoselect mode. See the “Reset
Command” section, next.
See also “Requirements for Reading Array Data” in the
“Device Bus Operations” section for more information.
The Read Operations table provides the read parame-
ters, and Figure 13 shows the timing diagram.
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.
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.
The reset command may be written between the se-
quence cycles in a program command sequence
before 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 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).
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).
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 13 shows the address and data requirements.
The autoselect command sequence is initiated by writ-
ing two unlock cycles, followed by the autoselect
command. The device then enters the autoselect mode,
and the system may read any number of autoselect
codes without reinitiating the command sequence.
Tables 13 and 14 show the address and data require-
ments for the command sequence. To determine sec-
tor protection information, the system must write to the
20
Am29PL320D
appropriate sector address (SA). Tables 4 and 6 show
the address range associated with each sector.
The system must write the reset command to exit the
autoselect mode and return to reading array data.
Enter SecSi™ Sector/Exit SecSi Sector
Command Sequence
The SecSi Sector region provides a secured data area
containing a random, eight-word (or four double word)
electronic serial number (ESN). The system can ac-
cess the SecSi Sector region by issuing the three-
cycle Enter SecSi Sector command sequence. The
device continues to access the SecSi Sector region
until the system issues the four-cycle Exit SecSi Sec-
tor command sequence. The Exit SecSi Sector com-
m an d se q u en ce r e tu r ns t h e d ev ic e t o n o r m a l
operation. Table 13 shows the address and data re-
quirements for both command sequences. See also
“ S e c S i ™ ( S e c u r e d
Memory Region” for further information.
Word/Double Word Program
Command Sequence
The system may program the device by word or double
word, depending on the state of the WORD# input.
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 13 shows the address and data re-
quirements for the program command sequence.
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
determine the status of the program operation by using
DQ7 or DQ6. See “Write Operation Status” for informa-
tion on these status bits.
Any commands written to the device during the Em-
bedded Program Algorithm are ignored. The Program
command sequence should be reinitiated once the de-
vice 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”.
S i l i c o n ) S e c t o r
October 2, 2003
F l a s h