EN25S20A Datasheet, PDF (46/65 Pages) Eon Silicon Solution Inc. – 2 Megabit 1.8V Serial Flash Memory with 4Kbyte Uniform Sector

EN25S20A
The instruction sequence is shown in Figure 35. The Read Identification (RDID) instruction is
terminated by driving Chip Select High at any time during data output.
When Chip Select is driven High, the device is put in the Standby Power mode. Once in the Standby
Power mode, the device waits to be selected, so that it can receive, decode and execute instructions.
The Read Identification (RDID) instruction is available in Standard SPI Mode only.
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 63, 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.
This Data Sheet may be revised by subsequent versions
46
or modifications due to changes in technical specifications.
©2014 Eon Silicon Solution, Inc.,
Rev. A, Issue Date: 2014/01/16
www.eonssi.com