EN25B64 Datasheet, PDF (27/37 Pages) Eon Silicon Solution Inc. – 64 Megabit Serial Flash Memory with Boot and Parameter Sectors

EN25B64
Enter OTP Mode (3Ah)
This Flash has an extra 512 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 0 ( bottom boot ) or sector 131 ( top boot ) respectively, SRP bit
becomes OTP_LOCK bit and can be read with 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 BP [2:0] = ‘000’. 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 19. Enter OTP Mode
Table 7a. Bottom Boot Security Sector Address
Sector Size
(bytes)
512
Address Range
Byte mode (x8)
000000h – 0001FFh
Table 7b. Top Boot Security Sector Address
Sector Size
(bytes)
512
Address Range
Byte mode (x8)
7FFE00h – 7FFFFFh
This Data Sheet may be revised by subsequent versions ₂₇ ©2004 Eon Silicon Solution, Inc., www.essi.com.tw
or modifications due to changes in technical specifications.
Rev. C, Issue Date: 2008/06/23