11.2.27 Enter Secured OTP (B1h)
The Enter Secured OTP instruction is for entering the additional 4K-bit secured OTP mode. The
additional 4K-bit secured OTP is independent from main array, which may be used to store unique
serial number for system identifier. After entering the Secured OTP mode, and then follow standard
read or program, procedure to read out the data or update data. The Secured OTP data cannot be
updated again once it is lock-down
Please note that WRSR/WRSCUR commands are not acceptable during the access of secure
OTP region, once security OTP is lock down, only commands related with read are valid.
The Enter Secured OTP instruction sequence is shown in figure 27.
6 7 Mode3
Figure 27. Enter Secured OTP instruction sequence
11.2.28 Exit Secured OTP (C1h)
The Exit Secured OTP instruction is for exiting the additional 4K-bit secured OTP mode.
The Exit Secured OTP instruction sequence is shown in figure 28
7 Mode 3
Figure 28. Exit Secured OTP instruction sequence