EN25F40
Figure 19. Read Identification (RDID)
Enter OTP Mode (3Ah)
This Flash has a extra 256 bytes OTP sector, user must issue ENTER OTP MODE command to enter
OTP mode before reading / programming or erasing OTP sector. After entering OTP mode, the OTP
sector is mapping to sector 127, SRP bit becomes OTP_LOCK bit and can be reading by RDSR
command. Program / Erase command will be disabled when OTP_LOCK is ‘1’
WRSR command will ignore the input data and program LOCK_BIT to 1.
User must clear the protect bits before enter OTP mode.
OTP sector can only be program and erase when LOCK_BIT equal ‘0’ and sector 127 not protected. In
OTP mode, user can read other sectors, but program/erase other sectors only allowed when OTP_LOCK
equal ‘0’.
User can use WRDI (04H) command to exit OTP mode.
Figure 20. Enter OTP Mode
This Data Sheet may be revised by subsequent versions
or modifications due to changes in technical specifications.
©2004 Eon Silicon Solution, Inc., www.essi.com.tw
20
Rev. B, Issue Date: 2007/05/09
EON [ EON SILICON SOLUTION INC. ]
