 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
M410000026 Datasheet(PDF) 25 Page - Advanced Micro Devices |
|
||||||||||||||||||||||||||||||
M410000026 Datasheet(HTML) 25 Page - Advanced Micro Devices |
|
|
25 / 65 page  24 Am41DL32x4G November 12, 2001 P R E L IMINARY 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 uses a SecSi Sector Indica- tor Bit 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 fac tor y l o c k ed or c u s tomer lo c k abl e. The 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 unprotected, allowing cus- tomers 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 customer-lockable devices from being used to replace devices 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 addresses 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 boot sectors. 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 available preprogrammed with a random, se- cure ESN only. In the Top Boot device the ESN is located at ad- dresses 1FF000h–1FF007h in word mode (or ad- dresses 3FE000h–3FE00Fh in byte mode). In the Bottom Boot device the ESN is located at addresses 0 000 0h – 000 07F h i n w o r d mo de ( o r 000000h–0000FFh in byte mode). 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, expanding the size of the available Flash array. The SecSi Sector can be read any number of times, but can be programmed and locked only once, and cannot be erased. Note that the accelerated 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: s 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 V IH or VID. This allows in-system protection of the without raising any device pin to a high voltage. Note that this method is only applicable to the SecSi Sector. s Write the three-cycle Enter SecSi Sector Region command sequence, and then use the alternate method of sector protection described in the “Sec- tor/Sector Block Protection and Unprotection”. Once the SecSi Sector is locked and verified, the sys- te m mus t wr i t e the E x i t Sec S i Sec tor Regi on command 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 available for unprotecting the SecSi Sector area and none of the bits in the SecSi Sector memory space can be modified in any way. Hardware Data Protection The command sequence requirement of unlock cycles for programming or erasing provides data protection against inadvertent writes (refer to Tables 15 and 17 for command definitions). In addition, the following hardware data protection measures prevent accidental erasure or programming, which might otherwise be caused by spurious system level signals during V CC power-up and power-down transitions, or from system noise. Low V CC Write Inhibit When V CC is less than VLKO, the device does not ac- cept any write cycles. This protects data during V CC power-up and power-down. The command register and all internal program/erase circuits are disabled, and the device resets to reading array data. Subse- quent writes are ignored until V CC is greater than VLKO. The system must provide the proper signals to the control pins to prevent unintentional writes when V CC is greater than V LKO. Write Pulse “Glitch” Protection Noise pulses of less than 5 ns (typical) on OE#, CE#f or WE# do not initiate a write cycle. |
Similar Part No. - M410000026 |
|
Similar Description - M410000026 |
|
|
Link URL |
| Privacy Policy |
| ALLDATASHEET.COM |
| Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
| Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
|
Family Site : ic2ic.com |
icmetro.com |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
