S71AL016D SPANSION [SPANSION], S71AL016D Datasheet - Page 21

• Manufacturer Part Number: S71AL016D
• Description: Stacked Multi-Chip Product (MCP) Flash Memory and RAM
• Manufacturer: SPANSION [SPANSION]

August 4, 2004 S29AL016D_00_A1_E
Temporary Sector Unprotect
It is possible to determine whether a sector is protected or unprotected. See “Au-
toselect Mode” for details.
Sector protection/unprotection can be implemented via two methods.
The primary method requires V
mented either in-system or via programming equipment.
algorithms and
microprocessor bus cycle timing. For sector unprotect, all unprotected sectors
must first be protected prior to the first sector unprotect write cycle.
The alternate method intended only for programming equipment requires V
address pin A9 and OE#. This method is compatible with programmer routines
written for earlier 3.0 volt-only Spansion flash devices. Details on this method are
provided in a supplement, publication number 21468. Contact a Spansion repre-
sentative to request a copy.
This feature allows temporary unprotection of previously protected sectors to
change data in-system. The Sector Unprotect mode is activated by setting the
RESET# pin to V
grammed or erased by selecting the sector addresses. Once V
the RESET# pin, all the previously protected sectors are protected again. shows
the algorithm, and
A d v a n c e
Figure 1. Temporary Sector Unprotect Operation
Notes:
1. All protected sectors unprotected.
2. All previously protected sectors are protected once
Figure 23
again.
ID
. During this mode, formerly protected sectors can be pro-
Figure 22
shows the timing diagram. This method uses standard
I n f o r m a t i o n
shows the timing diagrams, for this feature.
ID
Unprotect Completed
Program Operations
S29AL016D
on the RESET# pin only, and can be imple-
Temporary Sector
Perform Erase or
RESET# = V
RESET# = V
(Note 1)
(Note 2)
START
ID
IH
Figure 2
ID
is removed from
shows the
ID
on
21