MX25L12835F
II. Additional 4K-bit secured OTP for unique identifier: to provide 4K-bit one-time program area for setting de-
vice unique serial number - Which may be set by factory or system customer.
- Security register bit 0 indicates whether the chip is locked by factory or not.
- To program the 4K-bit secured OTP by entering 4K-bit secured OTP mode (with Enter Security OTP command),
and going through normal program procedure, and then exiting 4K-bit secured OTP mode by writing Exit Security
OTP command.
- Customer may lock-down the customer lockable secured OTP by writing WRSCUR(write security register) com-
mand to set customer lock-down bit1 as "1". Please refer to "Table 9. Security Register Definition" for security
register bit definition and "Table 3. 4K-bit Secured OTP Definition" for address range definition.
- Note: Once lock-down whatever by factory or customer, it cannot be changed any more. While in 4K-bit secured
OTP mode, array access is not allowed.
Table 3. 4K-bit Secured OTP Definition
Address range
xxx000~xxx00F
xxx010~xxx1FF
Size
Standard Factory Lock
ESN (electrical serial number)
N/A
Customer Lock
128-bit
3968-bit
Determined by customer
P/N: PM1795
REV. 1.0, OCT. 23, 2012
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