D a t a S h e e t
10.3 Autoselect Command Sequence
The autoselect command sequence allows the host system to read several identifier codes at specific
addresses:
A7:A0
(x16)
A6:A-1
(x8)
Identifier Code
Manufacturer ID
00h
01h
00h
02h
Device ID, Cycle 1
Device ID, Cycle 2
0Eh
1Ch
Device ID, Cycle 3
0Fh
1Eh
Secured Silicon Sector Factory Protect
Sector Protect Verify
03h
06h
(SA)02h
(SA)04h
Note
The device ID is read over three cycles. SA = Sector Address
The autoselect command sequence is initiated by first writing on unlock cycle (two 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:
The system must write the reset command to return to the read mode (or erase-suspend-read mode if the
device was previously in Erase Suspend).
10.4 Enter/Exit Secured Silicon Sector Command Sequence
The Secured Silicon Sector region provides a secured data area containing an 8-word/16-byte random
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 Silicon Sector command sequence.
The Exit Secured Silicon Sector command sequence returns the device to normal operation. Table 10.1
on page 51 and Table 10.3 on page 53 show the address and data requirements for both command
sequences. See also Secured Silicon Sector Flash Memory Region on page 35 for further information. Note
that the ACC function and unlock bypass modes are not available when the Secured Silicon Sector is
enabled.
10.4.1
Word 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 10.1 on page 51 and Table 10.3 on page 53 show the address and data
requirements for the word program command sequence, respectively.
When the Embedded Program algorithm is complete, the device then returns to the read mode and
addresses are no longer latched. The system can determine the status of the program operation by using
DQ7 or DQ6. Refer to the Write Operation Status section for information on these status bits. Any commands
written to the device during the Embedded Program Algorithm are ignored. Note that the Secured Silicon
Sector, autoselect, and CFI functions are unavailable when a program operation is in progress. Note that a
hardware reset immediately terminates the program operation. The program command sequence should be
reinitiated once the device returns to the read mode, to ensure data integrity.
Programming is allowed in any sequence of address locations and across sector boundaries. Programming
to the same word address multiple times without intervening erases (incremental bit programming) requires a
modified programming method. For such application requirements, please contact your local Spansion
representative. Word programming is supported for backward compatibility with existing Flash driver software
and for occasional writing of individual words. Use of write buffer programming (see below) is strongly
recommended for general programming use when more than a few words are to be programmed. The
effective word programming time using write buffer programming is approximately four times shorter than the
single word programming time.
42
S29GL-N MirrorBit® Flash Family
S29GL-N_01_09 November 16, 2007
SPANSION [ SPANSION ]
