AM29LV065DU101REF datasheet(21/54 Pages) AMD

21 / 54 page

February 16, 2006

Am29LV065D

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 256 bytes 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 permanently set at

the factory and cannot be changed, which prevents

cloning of a factory locked part. This ensures the secu-

rity of the ESN once the product is shipped to the field.

AMD offers the device with the SecSi Sector either

fa cto r y locked or c u stomer lock able. The fa c-

tory-locked version is always protected when shipped

from the factory, and has the SecSi (Secured Silicon)

Sector Indicator Bit permanently set to a “1.” The cus-

tomer-lockable version is shipped with the SecSi Sec-

tor unprotected, allowing customers to utilize that

sector in any manner they choose. The customer-lock-

able version also has the SecSi Sector Indicator Bit

permanently set to a “0.” Thus, the SecSi Sector Indi-

cator Bit prevents customer-lockable devices from

being used to replace devices that are factory locked.

The SecSi sector address space in this device is allo-

cated as follows:

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 first sector (SA0).

This mode of operation continues until the system is-

sues 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

sending commands to sector SA0.

Factory Locked: SecSi Sector Programmed and

Protected At the Factory

In devices with an ESN, the SecSi Sector is protected

when the device is shipped from the factory. The SecSi

Sector cannot be modified in any way. A factory locked

device has an 16-byte random ESN at addresses

000000h–00000Fh.

Customers may 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

SecSi Sector permanently locked. Contact an AMD

representative for details on using AMD’s Express-

Flash service.

Customer Lockable: SecSi Sector NOT

Programmed or Protected At the Factory

As an alternative to the factory-locked version, the de-

vice may be ordered such that the customer may pro-

gram and protect the 256-byte SecSi sector. The

SecSi Sector is one-time programmable, may not be

erased, and can be locked only once. Note that the ac-

celerated programming (ACC) and unlock bypass

functions are not available when programming the

SecSi Sector.

The SecSi Sector area can be protected using one of

the following procedures:

■ Write the three-cycle Enter SecSi Sector Region

command sequence, and then follow the in-system

sector protect algorithm as shown in Figure 2, ex-

cept that RESET# may be at either VIH or VID. This

allows in-system protection of the SecSi Sector

without raising any device pin to a high voltage.

Note that this method is only applicable to the SecSi

Sector.

■ To verify the protect/unprotect status of the SecSi

Sector, follow the algorithm shown in Figure 3.

Once the SecSi Sector is locked and verified, the sys-

tem must write the Exit SecSi Sector Region com-

mand sequence to return to reading and writing the

remainder of the array.

The SecSi Sector protection must be used with cau-

tion since, once protected, there is no procedure avail-

able for unprotecting the SecSi Sector area and none

of the bits in the SecSi Sector memory space can be

modified in any way.

Table 5.

SecSi Sector Contents

SecSi Sector

Address Range

Standard

Factory Locked

ExpressFlash

Factory Locked

Customer

Lockable

000000h–00000Fh

ESN

ESN or

determined by

customer

Determined by

customer

000010h–00007Fh,

000400h–00047Fh

Unavailable

Determined by

customer

AM29LV065DU101REF Datasheet(PDF) 21 Page - Advanced Micro Devices

AM29LV065DU101REF Datasheet(HTML) 21 Page - Advanced Micro Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54

Datasheet Download

Link URL