D A T A S H E E T
The Read-Only Operations table provides the read pa-
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 the read mode. If the de-
vice entered the autoselect mode while in the Erase
Suspend mode, writing the reset command returns the
device to the erase-suspend-read mode.
rameters, and Figure 14 shows the timing diagram.
Reset Command
Writing the reset command resets the device to the
read or erase-suspend-read mode. Address bits are
don’t cares for this command.
If DQ5 goes high during a program or erase operation,
writing the reset command returns the device to the
read mode (or erase-suspend-read mode if the device
was in Erase Suspend).
The reset command may be written between the se-
quence cycles in an erase command sequence before
erasing begins. This resets the device to the read
mode. Once erasure begins, however, the device ig-
nores reset commands until the operation is complete.
Note that if DQ1 goes high during a Write Buffer Pro-
gramming operation, the system must write the
Write-to-Buffer-Abort Reset command sequence to
reset the device for the next operation.
The reset command may be written between the
sequence cycles in a program command sequence
before programming begins. This resets the device to
the read mode. If the program command sequence is
written while the device is in the Erase Suspend mode,
writing the reset command returns the device to the
erase-suspend-read mode. Once programming be-
gins, however, the device ignores reset commands
until the operation is complete.
Autoselect Command Sequence
The autoselect command sequence allows the host
system to read several identifier codes at specific ad-
dresses:
A7:A0
(x16)
A6:A-1
(x8)
Identifier Code
Manufacturer ID
Device ID, Cycle 1
00h
01h
00h
02h
Device ID, Cycle 2
0Eh
1Ch
Device ID, Cycle 3
0Fh
1Eh
SecSi Sector Factory Protect
Sector Protect Verify
03h
06h
(SA)02h
(SA)04h
Note: The device ID is read over three cycles. SA = Sector Address
Tables 10 and 11 show the address requirements and
codes. This method is an alternative to that shown in
Table 3, which is intended for PROM programmers
and requires VID on address pin A9. The autoselect
command sequence may be written to an address that
is either in the read or erase-suspend-read mode. The
autoselect command may not be written while the de-
vice is actively programming or erasing.
Sector command sequence. The device continues to
access the SecSi Sector region until the system is-
sues the four-cycle Exit SecSi Sector command se-
quence. The Exit SecSi Sector command sequence
returns the device to normal operation. Tables 10 and
11 show the address and data requirements for both
command sequences. See also “SecSi (Secured Sili-
con) Sector Flash Memory Region” for further informa-
tion. Note that the ACC function and unlock bypass
modes are not available when the SecSi Sector is en-
abled.
The autoselect command sequence is initiated by first
writing two unlock cycles. This is followed by a third
write cycle that contains the autoselect command. The
device then enters the autoselect mode. The system
may read at any address any number of times without
initiating another autoselect command sequence:
Word/Byte 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 provides
internally generated program pulses and verifies the
programmed cell margin. Tables 10 and 11 show the
address and data requirements for the word/byte pro-
gram command sequence, respectively.
The system must write the reset command to return to
the read mode (or erase-suspend-read mode if the de-
vice was previously in Erase Suspend).
Enter SecSi Sector/Exit SecSi Sector
Command Sequence
The SecSi Sector region provides a secured data area
containing an 8-word/16-byte random Electronic Serial
Number (ESN). The system can access the SecSi
Sector region by issuing the three-cycle Enter SecSi
December 14, 2005
Am29LV640MH/L
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SPANSION [ SPANSION ]
