AM29PDL128G datasheet(29/69 Pages) SPANSION

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Am29PDL128G

July 29, 2002

P R E L I M I NARY

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 RE-

SET# pin to V

ID. During this mode, formerly protected

sectors can be programmed or erased by selecting the

sector addresses. Once V

ID is removed from the RE-

SET# pin, all the previously protected sectors are

protected again. Figure 2 shows the algorithm, and

Figure 23 shows the timing diagrams, for this feature.

Figure 2.

Temporary Sector Unprotect Operation

SecSi™ (Secured Silicon) Sector

Flash Memory Region

The SecSi (Secured Silicon) Sector feature provides a

Flash memory region that enables permanent part

identification through an Electronic Serial Number

(ESN). The SecSi Sector is 128 words (64 double

words) in length, and uses a SecSi Sector Indicator Bit

(DQ7) to indicate whether or not the SecSi Sector is

locked when shipped from the factory. This bit is per-

manently 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 SecSi Sector either

fa ct or y loc k ed o r c u s t om er l o c k able . Th e fac -

tory-locked version is always protected when shipped

from the factory, and has the SecSi Sector Indicator

Bit permanently set to a “1.” The customer-lockable

version is shipped with the SecSi Sector unprotected,

allowing customers to utilize the that sector in any

manner they choose. The customer-lockable version

has the SecSi Sector Indicator Bit permanently set to a

“0.” Thus, the SecSi Sector Indicator Bit prevents cus-

tomer-lockable devices from being used to replace de-

vices that are factory locked.

The system accesses the SecSi Sector through a

command sequence (see Enter SecSi Sector/Exit

SecSi Sector Command Sequence). After the system

has written the Enter SecSi Sector command se-

quence, it may read the SecSi Sector by using the ad-

dresses normally occupied by the boot sectors. This

mode of operation continues until the system issues

the Exit SecSi Sector command sequence, or until

power is removed from the device. On power-up, or

following a hardware reset, the device reverts to send-

ing commands to the normal address space.

Factory Locked: SecSi Sector Programmed and

Protected At the Factory

In a factory locked device, the SecSi Sector is pro-

tected when the device is shipped from the factory.

The SecSi Sector cannot be modified in any way. The

device is preprogrammed with both a random number

and a secure ESN. The SecSi Sector is located at ad-

dres s e s 000000h – 00007Fh in w o rd m o d e ( o r

000000h–00003Fh in double word mode). The device

is available preprogrammed with one of the following:

s A random, secure ESN only

s Customer code through the ExpressFlash service

s Both a random, secure ESN and customer code

through the ExpressFlash service.

Customers may opt to have their code programmed by

AMD through the AMD ExpressFlash service. AMD

programs the customer’s code, with or without the ran-

dom ESN. The devices are then shipped from AMD’s

factory with the SecSi Sector permanently locked.

Contact an AMD representative for details on using

AMD’s ExpressFlash service.

Customer Lockable: SecSi Sector NOT

Programmed or Protected At the Factory

If the security feature is not required, the SecSi Sector

can be treated as an additional Flash memory space.

The SecSi Sector can be read any number of times,

but can be programmed and locked only once. Note

that the accelerated programming (ACC) and unlock

bypass functions are not available when programming

the SecSi Sector.

START

Perform Erase or

Program Operations

RESET# = V

Temporary Sector

Unprotect Completed

(Note 2)

RESET# = V

(Note 1)

Notes:

1. All protected sectors unprotected (If WP# = V

IL, sectors

0, 1, 268, and 269 will remain protected).

2. All previously protected sectors are protected once

again.

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