EN25Q128
Figure 25.1. Read Identification (RDID) under EQPI Mode
Enter OTP Mode (3Ah)
This Flash has an extra 512 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 4095,
SRP bit becomes OTP_LOCK bit and can be read with RDSR command. Program / Erase command
will be disabled when OTP_LOCK bit 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 is set to ‘1’ and BP [3:0] = ‘0000’. In
OTP mode, user can read other sectors, but program/erase other sectors only allowed when
OTP_LOCK bit equal to ‘0’.
User can use WRDI (04h) command to exit OTP mode.
While in OTP mode, user can use Sector Erase (20h) command only to erase OTP data.
The instruction sequence is shown in Figure 26.1 while using the Enable Quad Peripheral Interface mode
(EQPI) (38h) command.
Table 7. OTP Sector Address
Sector
4095
Sector Size
512 byte
Address Range
FFF000h – FFF1FFh
Note: The OTP sector is mapping to sector 4095
This Data Sheet may be revised by subsequent versions
or modifications due to changes in technical specifications.
©2004 Eon Silicon Solution, Inc., www.eonssi.com
43
Rev. J, Issue Date: 2011/09/19
EON [ EON SILICON SOLUTION INC. ]
