A d v a n c e I n f o r m a t i o n
Reset Command
Writing the reset command to the device resets the device to reading array data. Address bits are
don’t care for this command.
The reset command may be written between the sequence cycles in an erase command sequence
before erasing begins. This resets the device to reading array data. Once erasure begins, however,
the device ignores reset commands until the operation is complete.
The reset command may be written between the sequence cycles in a program command se-
quence 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 sequence cycles in an autoselect command se-
quence. 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 reading array data (also applies during Erase Suspend).
Autoselect Command Sequence
The autoselect command sequence allows the host system to access the manufacturer and de-
vices codes, and determine whether a sector is protected. Table 17 on page 38 shows the address
and data requirements. This method is an alternative to that shown in Table 8 on page 20, which
is intended for PROM programmers and requires V on address bit A9.
ID
The autoselect command sequence is initiated by writing two unlock cycles, followed by the au-
toselect command. The device then enters the autoselect mode, and the system may read at any
address any number of times, without initiating another command sequence.
A read cycle at address 0XXX00h retrieves the manufacturer code. A read cycle at address
0XXX01h returns the device code. A read cycle containing a sector address (SA) and the address
02h in word mode (or 04h in byte mode) returns 01h if that sector is protected, or 00h if it is
unprotected. Refer to Table 2 on page 14 and Table 4 on page 16 for valid sector addresses.
The system must write the reset command to exit the autoselect mode and return to reading
array data.
Enter Secured SiliconSector/Exit Secured Silicon Sector
Command Sequence
The Secured Silicon Sector region provides a secured data area containing a random, sixteen-
byte electronic serial number (ESN). The system can access the Secured Silicon Sector region by
issuing the three-cycle Enter Secured Silicon Sector command sequence. The device continues to
access the Secured Silicon Sector region until the system issues the four-cycle Exit Secured Sili-
con Sector command sequence. The Exit Secured Silicon Sector command sequence returns the
device to normal operation. Table 16. S29AL032D Command Definitions — Model 00 on page 37
and Table 17. S29AL032D Command Definitions — Models 03, 04 on page 38 show the ad-
dresses and data requirements for both command sequences. Note that the ACC function and
unlock bypass modes are not available when the device enters the Secured Silicon Sector. See
also Secured Silicon Sector Flash Memory Region on page 26 for further information.
Word/Byte Program Command Sequence
Models 03, 04 may program the device by word or byte, depending on the state of the BYTE#
pin. Model 00 may program the device by byte only. 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
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S29AL032D
S29AL032D_00_A3 June 13, 2005
SPANSION [ SPANSION ]
