AM29F400BB-70EF Spansion Inc., AM29F400BB-70EF Datasheet - Page 13

• Manufacturer Part Number: AM29F400BB-70EF
• Description: IC, FLASH, 4MBIT, 70NS, TSOP-48
• Manufacturer: Spansion Inc.

Specifications of AM29F400BB-70EF

• Memory Type: Flash
• Memory Size: 4Mbit
• Memory Configuration: 512K X 8 / 256K X 16
• Access Time: 70ns
• Supply Voltage Range: 4.5V To 5.5V
• Memory Case Style: TSOP
• No. Of Pins: 48
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

L = Logic Low = V
Sector Protection/Unprotection
The hardware sector protection feature disables both
program and erase operations in any sector. The hard-
ware sector unprotection feature re-enables both
program and erase operations in previously protected
sectors.
Sector protection/unprotection must be implemented
using programming equipment. The procedure
requires a high voltage (V
OE#. Details on this method are provided in a supple-
ment, publication number 20185. Contact an AMD
representative to obtain a copy of this document.
The device is shipped with all sectors unprotected.
AMD offers the option of programming and protecting
sectors 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 is protected
or unprotected. See “Autoselect Mode” for details.
Temporary Sector Unprotect
This feature allows temporary unprotection of previ-
ously protected sectors to change data in-system. The
Sector Unprotect mode is activated by setting the
RESET# pin to V
tected sectors can be programmed or erased by
selecting the sector addresses. Once V
from the RESET# pin, all the previously protected
sectors are protected again. Figure 1 shows the algo-
November 11, 2009 21505E8
Manufacturer ID: AMD
Device ID:
Am29F400B
(Top Boot Block)
Device ID:
Am29F400B
(Bottom Boot Block)
Sector Protection Verification
Description
IL
, H = Logic High = V
ID
. During this mode, formerly pro-
Mode
Word
Word
Byte
Byte
Table 4. Am29F400B Autoselect Codes (High Voltage Method)
ID
CE#
) on address pin A9 and
L
L
L
L
L
L
OE#
IH
L
L
L
L
L
L
, SA = Sector Address, X = Don’t care.
ID
WE#
H
H
H
H
H
H
is removed
D A T A
A17
A12
SA
to
X
X
X
Am29F400B
A11
A10
to
X
X
X
X
S H E E T
V
V
V
V
A9
rithm, and Figure 18 shows the timing diagrams, for this
feature.
Notes:
1. All protected sectors unprotected.
2. All previously protected sectors are protected once
Figure 1. Temporary Sector Unprotect Operation
ID
ID
ID
ID
again.
A8
A7
to
X
X
X
X
A6
L
L
L
L
A5
A2
to
X
X
X
X
Unprotect Completed
Program Operations
Temporary Sector
Perform Erase or
A1
H
L
L
L
RESET# = V
RESET# = V
(Note 1)
(Note 2)
START
A0
H
H
L
L
DQ15
DQ8
22h
22h
ID
IH
to
X
X
X
X
X
(unprotected)
(protected)
DQ7
DQ0
ABh
ABh
01h
23h
23h
01h
00h
to
11