AM29F017B Advanced Micro Devices, AM29F017B Datasheet - Page 11

• Manufacturer Part Number: AM29F017B
• Description: 16 Megabit (2 M x 8-Bit) CMOS 5.0 Volt-only/ Uniform Sector Flash Memory
• Manufacturer: Advanced Micro Devices

Autoselect Mode
The autoselect mode provides manufacturer and de-
vice identification, and sector protection verification,
through identifier codes output on DQ7–DQ0. This
mode is primarily intended for programming equipment
to automatically match a device to be programmed with
its corresponding programming algorithm. However,
the autoselect codes can also be accessed in-system
through the command register.
When using programming equipment, the autoselect
mode requires V
A9. Address pins A6, A1, and A0 must be as shown in
Autoselect Codes (High Voltage Method) table. In ad-
dition, when verifying sector protection, the sector ad-
L = Logic Low = V
Sector Group Protection/Unprotection
The hardware sector group protection feature dis-
ables both program and erase operations in any sec-
tor. Each sector group consists of four adjacent
sectors. Table 4 shows how the sectors are goruped,
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 sectors.
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, publication number 21544. Contact an
AMD representative to obtain a copy of the appropriate
document.
The device is shipped with all sector groups unpro-
tected. AMD offers the option of programming and pro-
tecting 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 group is
protected or unprotected. See “Autoselect Mode” for
details.
Manufacturer ID:
AMD
Device ID:
Am29F017B
Sector Group
Protection
Verification
Description
IL
ID
, H = Logic High = V
CE# OE# WE# A20-A18 A17-A10
(11.5 V to 12.5 V) on address pin
L
L
L
Table 3. Am29F017B Autoselect Codes (High Voltage Method)
ID
L
L
L
) on address pin A9 and the
H
H
H
IH
Address
, SA = Sector Address, X = Don’t care.
Sector
Group
X
X
Am29F017B
X
X
X
V
V
V
A9
ID
ID
ID
dress must appear on the appropriate highest order
address bits. Refer to the corresponding Sector Ad-
dress Tables. The Command Definitions table shows
the remaining address bits that are don’t care. When all
necessary bits have been set as required, the program-
ming equipment may then read the corresponding
identifier code on DQ7–DQ0.
To access the autoselect codes in-system, the host
system can issue the autoselect command via the
command register, as shown in the Command Defini-
tions table. This method does not require V
“Command Definitions” for details on using the autose-
lect mode.
Temporary Sector Group Unprotect
This feature allows temporary unprotection of previ-
ously protected sectors 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/Sector Group Unprotect dia-
gram shows the timing waveforms, for this feature.
Sector
Group
SGA0
SGA1
SGA2
SGA3
SGA4
SGA5
SGA6
SGA7
A8-A7
X
X
X
ID
Table 4. Sector Group Addresses
is removed from the RESET# pin, all the
A6
V
V
V
IL
IL
IL
A20
0
0
0
0
1
1
1
1
p r o t e c t e d
A5-A2
X
X
X
A19
0
0
1
1
0
0
1
1
V
V
V
A1
IH
IL
IL
s e c t o r
V
V
V
A0
IH
IL
IL
A18
ID
0
1
0
1
0
1
0
1
. During this mode,
00h (unprotected)
01h (protected)
g r o u p s
DQ7-DQ0
SA12
SA16
SA20
SA24
SA28
SA8
SA0
SA4
3Dh
01h
Sectors
–
–
–
–
–
–
–
–
SA11
SA3
SA7
SA15
SA19
SA23
SA27
SA31
ID
. See
a r e
11