MX29LV320E 查看數據表（PDF） - Macronix International
零件编号
产品描述 (功能)
生产厂家
MX29LV320E Datasheet PDF : 68 Pages
| |||
MX29LV320E T/B
COMMAND OPERATIONS (cont'd)
CUSTOMER LOCKABLE: SECURITY SECTOR NOT PROGRAMMED OR PROTECTED AT THE FACTORY
When the security feature is not required, the Security Sector can provide an extra sector of memory.
Two methods are available for protecting the Security Sector. Note that once the Security Sector is protected,
there is NO way to unprotect it and its contents can no longer be altered.
The first protection method requires writing the three-cycle Enter Security Region command followed by the
use of the Sector-Group protect algorithm as illustrated in Figure 14 with the following exception: the RESET#
pin may be at either Vih or Vhv. Unlike normal Sector-Groups, which do require Vhv on the RESET# pin, the
Security Sector may be permanently locked in-circuit without the use of high voltage.
The second protection method also uses the three-cycle Enter Security Region command, but uses bus
operations that applies Vhv to the A9 and OE# pins with A6, CE#, and WE# held LOW and the SA address
applied to A20 to A12. The protection operation begins at the falling edge of WE# and terminates at the rising
edge. Contact Macronix for more details on using this method.
After the Security Sector is locked and verified, the system must write an Exit Security Sector Region command,
go through a power cycle, or issue a hardware reset to return the device to read normal array mode.
ENTER AND EXIT SECURITY SECTOR
The device allows the user to access the extra 256-Byte sector identified as the Security Sector, which may con-
tain a random, 128-bits electronic serial number (ESN), or it may contain user data.
To access the Security Sector, the user must issue a three-cycle "Enter Security Sector" command sequence. To
exit the Security Sector and return to normal operation, the user issues the four-cycle "Exit Security Sector" com-
mand. Before issuing the "Exit Security Sector" command, please ensure the entering of security sector region.
P/N:PM1575
REV. 1.3, DEC. 19, 2013
28
Share Link: 