EN25F40A Datasheet, PDF (43/62 Pages) Eon Silicon Solution Inc. – 4 Megabit Serial Flash Memory with 4Kbyte Uniform Sector

EN25F40A
Figure 28.1. Read Identification (RDID) in QPI 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 127, SRP
bit becomes OTP_LOCK bit and can be read with RDSR command. The Chip Erase, Bank Erase and
Half Bank Erase 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 28.1 while using the Enable Quad Peripheral Interface mode
(EQPI) (38h) command.
Erase OTP Command (20h)
User only can use Sector Erase (20h) command to erase OTP data.
Table 7. 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
43
or modifications due to changes in technical specifications.
©2013 Eon Silicon Solution, Inc.,
Rev. A, Issue Date: 2013/11/18
www.eonssi.com