EN25LF40_1 Datasheet, PDF (23/35 Pages) Eon Silicon Solution Inc. – 4 Megabit Serial Flash Memory with 4Kbytes Uniform Sector

EN25LF40
Enter OTP Mode (3Ah)
This Flash has an extra 256 bytes OTP sector, user must issue ENTER OTP MODE command to read,
program or erase OTP sector. After entering OTP mode, the OTP sector is mapping to sector 127, 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 OTP_LOCK bit to 1.
User must clear the protect bits before enter OTP mode.
OTP sector can only be program and erase before OTP_LOCK bit equal ‘1’ and BP [2:0] = ‘000’. In OTP
mode, user can read other sectors, but program/erase other sectors only allowed when OTP_LOCK bit equal
‘0’.
User can use WRDI (04h) command to exit OTP mode.
Erase OTP Command (20h)
User can use Sector Erase (20h) command only to erase OTP data.
Table 7. OTP Sector Address
Sector
127
Sector Size
256 byte
Address Range
07F000h – 07F0FFh
Note: The OTP sector is mapping to sector 127
Figure 20. Enter OTP Mode
This Data Sheet may be revised by subsequent versions
23
or modifications due to changes in technical specifications.
©2004 Eon Silicon Solution, Inc.,
Rev. G, Issue Date: 2010/05/31
www.eonssi.com