S29GL256N10TFI023 ETC, S29GL256N10TFI023 Datasheet - Page 52

• Manufacturer Part Number: S29GL256N10TFI023
• Description: MirrorBit Flash Family
• Manufacturer: ETC

52
that the ACC function and unlock bypass modes are not available when the SecSi
Sector is enabled.
The SecSi sector address space in this device is allocated as follows:
The system accesses the SecSi Sector through a command sequence (see “Write
Protect (WP#)”). After the system has written the Enter SecSi Sector command
sequence, it may read the SecSi Sector by using the addresses normally occupied
by the first sector (SA0). This mode of operation continues until the system issues
the Exit SecSi Sector command sequence, or until power is removed from the de-
vice. On power-up, or following a hardware reset, the device reverts to sending
commands to sector SA0.
Customer Lockable: SecSi Sector NOT Programmed or Protected
At the Factory
Unless otherwise specified, the device is shipped such that the customer may
program and protect the 256-byte SecSi sector.
The system may program the SecSi Sector using the write-buffer, accelerated
and/or unlock bypass methods, in addition to the standard programming com-
mand sequence. See Command Definitions.
Programming and protecting the SecSi Sector must be used with caution 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.
The SecSi Sector area can be protected using one of the following procedures:
Once the SecSi Sector is programmed, locked and verified, the system must write
the Exit SecSi Sector Region command sequence to return to reading and writing
within the remainder of the array.
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. An ESN Factory
Locked device has an 16-byte random ESN at addresses 000000h–000007h.
Please contact your sales representative for details on ordering ESN Factory
Locked devices.
Customers may opt to have their code programmed by the factory through the
ExpressFlash service (Express Flash Factory Locked). The devices are then
shipped from the factory with the SecSi Sector permanently locked. Contact your
sales representative for details on using the ExpressFlash service.
SecSi Sector Address Range
Write the three-cycle Enter SecSi Sector Region command sequence, and
then follow the in-system sector protect algorithm as shown in
cept that RESET# may be at either V
tion 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 algo-
rithm shown in
000000h–000007h
000008h–00007Fh
Figure
S29GLxxxN MirrorBitTM Flash Family
Determined by customer
Customer Lockable
1.
A d v a n c e
IH
or V
ESN Factory Locked
I n f o r m a t i o n
ID
Unavailable
. This allows in-system protec-
ESN
Determined by customer
ESN or determined by
Factory Locked
ExpressFlash
Figure
customer
2, ex-
27631A4 May 13, 2004