AM29F080B-75EI Spansion Inc., AM29F080B-75EI Datasheet - Page 10

• Manufacturer Part Number: AM29F080B-75EI
• Description: IC,EEPROM,NOR FLASH,1MX8,CMOS,TSSOP,40PIN,PLASTIC
• Manufacturer: Spansion Inc.

Legend: L = Logic Low = V
Note: The system may also autoselect information in-system via the command register. See Table 5.
Sector Group Protection/Unprotection
The hardware group sector protection feature dis-
ables both program and erase operations in any sec-
tor group. Each sector group consists of two adjacent
sectors. Table 4 shows how the sectors are grouped,
and the address range that each sector group con-
tains. The hardware sector group unprotection fea-
ture re-enables both program and erase operations in
previously protected sector groups.
Sector group protection/unprotection must be imple-
mented using programming equipment. The procedure
requires a high voltage (V
control pins. Details on this method are provided in a
supplement, listed in publication number 19945. Con-
tact an AMD representative to obtain a copy of the ap-
propriate document.
The device is shipped with all sectors unprotected.
AMD offers the option of programming and protecting
sector groups at its factory prior to shipping the device
through AMD’s ExpressFlash™ Service. Contact an
AMD representative for details.
It is possible to determine whether a sector group is
protected or unprotected. See “Autoselect Mode” for
details.
10
Manufacturer ID: AMD
Device ID: Am29F080B
Sector Group
Protection Verification
Sector
Group
SGA0
SGA1
SGA2
SGA3
SGA4
SGA5
SGA6
SGA7
Description
Table 4. Sector Group Addresses
A19
0
0
0
0
1
1
1
1
A18
Table 3. Am29F080B Autoselect Codes (High Voltage Method)
0
0
1
1
0
0
1
1
CE#
IL
ID
L
L
L
, H = Logic High = V
) on address pin A9 and the
A17
OE#
0
1
0
1
0
1
0
1
L
L
L
WE#
SA10
SA12
SA14
H
H
H
SA0
SA2
SA4
SA6
SA8
Sectors
P R E L I M I N A R Y
IH
–
–
–
–
–
–
–
–
, SGA = Sector Group Address, X = Don’t care.
SGA
A19
A12
SA1
SA3
SA5
SA7
SA9
SA11
SA13
SA15
to
X
X
Am29F080B
A11
A10
to
X
X
X
Temporary Sector Group Unprotect
This feature allows temporary unprotection of previ-
ously protected sector groups to change data in-sys-
tem. The Sector Group Unprotect mode is activated
by setting the RESET# pin to V
formerly protected sector groups can be programmed
or erased by selecting the sector group addresses.
Once V
p r e v i o u s l y
protected again. Figure 1 shows the algorithm, and
the Temporary Sector Group Unprotect diagram
shows the timing waveforms, for this feature.
V
V
V
Notes:
1. All protected sector groups unprotected.
2. All previously protected sector groups are protected
A9
ID
ID
ID
Figure 1. Temporary Sector Group Unprotect
once again.
A8
A7
to
X
X
X
ID
is removed from the RESET# pin, all the
A6
L
L
L
p r o t e c t e d
Temporary Sector Group
A5
A2
to
Program Operations
X
X
X
Completed (Note 2)
Operation
Perform Erase or
RESET# = V
RESET# = V
Unprotect
(Note 1)
START
A1
H
L
L
s e c t o r
ID
A0
H
. During this mode,
L
L
ID
IH
01h (protected)
g r o u p s
(unprotected)
DQ7
DQ0
D5h
01h
00h
to
21503C-6
a r e