s29al016m Meet Spansion Inc., s29al016m Datasheet - Page 22

• Manufacturer Part Number: s29al016m
• Description: 16 Megabits 2m X 8-bits / 1m X 16-bits
• Manufacturer: Meet Spansion Inc.

20
The Secured Silicon Sector area can be protected using one of the following
procedures:
Once the Secured Silicon Sector is programmed, locked and verified, the system
must write the Exit Secured Silicon Sector Region command sequence to return
to reading and writing within the remainder of the array.
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. An ESN Factory Locked device has a 16-byte random ESN at addresses
given in Table 5. Please contact your local sales office or representative for details
on ordering ESN Factory Locked devices.
Customers may opt to have their code programmed by the manufacturer
through the ExpressFlash service (Express Flash Factory Locked). The devices
are then shipped from the factory with the Secured Silicon Sector permanently
locked. Contact an sales office or representative for details on using the Ex-
pressFlash service.
Write the three-cycle Enter Secured Silicon Sector Region command se-
quence, and then follow the in-system sector protect algorithm as shown in
Figure 2, except that RESET# may be at either V
tem protection of the Secured Silicon Sector without raising any device pin to
a high voltage. Note that this method is only applicable to the Secured Silicon
Sector.
To verify the protect/unprotect status of the Secured Silicon Sector, follow the
algorithm shown in Figure 3.
Figure 3. Secured Silicon Sector Protect Verify
Write 40h to SecSi
Read from SecSi
Sector address
A1 = 1, A0 = 0
A1 = 1, A0 = 0
Sector address
Write 60h to
with A6 = 0,
with A6 = 0,
any address
RESET# =
Wait 1 ms
V
IH
START
or V
ID
S29AL016M
D a t a
Remove V
If data = 00h,
SecSi Sector is
If data = 01h,
SecSi Sector is
from RESET#
Protect Verify
unprotected.
SecSi Sector
Write reset
protected.
command
complete
S h e e t
IH
or V
IH
or V
ID
ID
. This allows in-sys-
S29AL016M_00_A7 October 11, 2006