AM29LV640MB90REI Spansion Inc., AM29LV640MB90REI Datasheet - Page 25

• Manufacturer Part Number: AM29LV640MB90REI
• Manufacturer: Spansion Inc.

Specifications of AM29LV640MB90REI

• Cell Type: NOR
• Density: 64Mb
• Access Time (max): 90ns
• Interface Type: Parallel
• Boot Type: Bottom
• Address Bus: 23/22Bit
• Operating Supply Voltage (typ): 3.3V
• Operating Temp Range: -40C to 85C
• Package Type: TSOP
• Program/erase Volt (typ): 3 to 3.6V
• Sync/async: Asynchronous
• Operating Temperature Classification: Industrial
• Operating Supply Voltage (min): 3V
• Operating Supply Voltage (max): 3.6V
• Word Size: 8/16Bit
• Number Of Words: 8M/4M
• Supply Current: 20mA
• Mounting: Surface Mount
• Pin Count: 48
• Lead Free Status / Rohs Status: Not Compliant

Secured Silicon Sector Flash
Memory Region
The Secured Silicon Sector feature provides a Flash
memory region that enables permanent part identifica-
tion through an Electronic Serial Number (ESN). The
Secured Silicon Sector is 128 words/256 bytes in
length, and uses a Secured Silicon Sector Indicator Bit
(DQ7) to indicate whether or not the Secured Silicon
Sector is locked when shipped from the factory. This
bit is permanently set at the factory and cannot be
changed, which prevents cloning of a factory locked
part. This ensures the security of the ESN once the
product is shipped to the field.
AMD offers the device with the Secured Silicon Sector
either factory locked or customer lockable. The fac-
tory-locked version is always protected when shipped
from the factory, and has the Secured Silicon Sector
Indicator Bit per manently set to a “1.” The cus-
tomer-lockable version is shipped with the Secured
Silicon Sector unprotected, allowing customers to pro-
gram the sector after receiving the device. The cus-
tomer-lockable version also has the Secured Silicon
Sector Indicator Bit permanently set to a “0.” Thus, the
Secured Silicon Sector Indicator Bit prevents cus-
tomer-lockable devices from being used to replace de-
vices that are factory locked.
The Secured Silicon sector address space in this de-
vice is allocated as follows:
The system accesses the Secured Silicon Sector
through a command sequence. See
S i l i c o n S e c t o r / E x i t S e c u r e d S i l i c o n S e c t o r
Command Sequence on page 28
written the Enter Secured Silicon Sector command se-
quence, it can read the Secured Silicon Sector by
using the addresses normally occupied by the first
sector (SA0). This mode of operation continues until
the system issues the Exit Secured Silicon Sector
command sequence, or until power is removed from
the device. On power-up, or following a hardware re-
set, the device reverts to sending commands to sector
SA0. Note that the ACC function and unlock bypass
modes are not available when the Secured Silicon
Sector is enabled.
February 1, 2007 26190C8
Secured Silicon Sector
000000h–
000008h–
00007Fh
000007h
x16
Address Range
Table 7. Secured Silicon Sector Contents
000000h–
000010h–
00000Fh
0000FFh
x8
Unavailable
Standard
Factory
Locked
ESN
Factory Locked
ExpressFlash
by customer
by customer
Determined
determined
After the system has
ESN or
Enter Secured
by customer
Determined
D A T A
Customer
Lockable
Am29LV640MT/B
S H E E T
Factory Locked: Secured Silicon Sector
Programmed and Protected At the Factory
In devices with an ESN, the Secured Silicon Sector is
protected when the device is shipped from the factory.
The Secured Silicon Sector cannot be modified in any
way. See
ing.
Customers can opt to have their code programmed by
AMD through the AMD ExpressFlash service. The de-
vices are then shipped from AMD’s factory with the
Secured Silicon Sector permanently locked. Contact
an AMD representative for details on using AMD’s Ex-
pressFlash service.
Customer Lockable: Secured Silicon Sector NOT
Programmed or Protected At the Factory
As an alternative to the factory-locked version, the de-
vice can be ordered such that the customer can pro-
gram and protect the 128-word/256 bytes Secured
Silicon sector.
The system can program the Secured Silicon Sector
using the write-buffer, accelerated and/or unlock by-
pass methods, in addition to the standard program-
ming command sequence. See
on page 27
Programming and protecting the Secured Silicon Sec-
tor must be used with caution since, once protected,
there is no procedure available for unprotecting the
Secured Silicon Sector area and none of the bits in the
Secured Silicon Sector memory space can be modi-
fied in any way.
The Secured Silicon Sector area can be protected
using one of the following procedures:
■ Write the three-cycle Enter Secured Silicon Sector
■ To verify the protect/unprotect status of the Secured
Once the Secured Silicon Sector is programmed,
locked and verified, the system must write the Exit Se-
cured Silicon Sector Region command sequence to
return to reading and writing within the remainder of
the array.
Region command sequence, and then follow the
in-system sector protect algorithm as shown in
ure
V
Silicon Sector without raising any device pin to a
high voltage. Note that this method is only applica-
ble to the Secured Silicon Sector.
Silicon Sector, follow the algorithm shown in
3.
ID
. This allows in-system protection of the Secured
2, except that RESET# can be at either V
Table 7
for Secured Silicon Sector address-
Command Definitions
Figure
IH
Fig-
23
or