EN25S40A Datasheet, PDF (48/68 Pages) Eon Silicon Solution Inc. – 4 Megabit 1.8V Serial Flash Memory with 4Kbyte Uniform Sector

EN25S40A
Figure 35. Read Identification (RDID)
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 127, SRP
bit becomes OTP_LOCK bit and can be read with RDSR command. The Chip Erase, Bank Erase, Half
Bank Erase, Suspend and Resume commands are also disabled.
In OTP mode, user can read other sectors, but program/erase other sectors only allowed when
OTP_LOCK bit equal to ‘0’.
WRSR command will ignore the input data and program OTP_LOCK bit to 1.
User can use WRDI (04H) command to exit OTP mode.
The instruction sequence is shown in Figure 36.1 while using the Enable Quad Peripheral Interface
mode (EQPI) (38h) command.
Erase OTP Command (20h)
User only can use Sector Erase (20h) command only to erase OTP data.
Table 10. OTP Sector Address
Sector
Sector Size
Address Range
127
512 byte
07F000h – 07F1FFh
Note: The OTP sector is mapping to sector 127
This Data Sheet may be revised by subsequent versions
48
or modifications due to changes in technical specifications.
©2013 Eon Silicon Solution, Inc.,
Rev. A, Issue Date: 2013/12/30
www.eonssi.com