This Data Sheet may be revised by subsequent versions

©2004 Eon Silicon Solution, Inc., www.essi.com.tw

or modifications due to changes in technical specifications.

9

EN25F40

Rev. B, Issue Date: 2007/05/09

Power-down

Manufacturer/

Device ID

90h

dummy

dummy

00h(5)

(M7-M0)

(ID7-ID0)

Read Identification

9Fh

(M7-M0)

(ID15-ID8)

(ID7-ID0)

Enter OTP mode

3Ah

Notes:

1. Data bytes are shifted with Most Significant Bit first. Byte fields with data in parenthesis “( )” indicate data being read from

the device on the DO pin.

2. The Status Register contents will repeat continuously until CS# terminate the instruction.

3. All sectors may use any address within the sector.

4. The Device ID will repeat continuously until CS# terminate the instruction.

5. The Manufacturer ID and Device ID bytes will repeat continuously until CS# terminate the instruction.

00h on Byte 4 starts with MID and alternate with DID, 01h on Byte 4 starts with DID and alternate with MID.

Table 5. Manufacturer and Device Identification

OP Code

(M7-M0)

(ID15-ID0)

(ID7-ID0)

ABh

12h

90h

1Ch

12h

9Fh

1Ch

3113h

Write Enable (WREN) (06h)

The Write Enable (WREN) instruction (Figure 5) sets the Write Enable Latch (WEL) bit. The Write Enable

Latch (WEL) bit must be set prior to every Page Program (PP), Sector Erase (SE), Block Erase (BE), Chip

Erase (CE) and Write Status Register (WRSR) instruction.

The Write Enable (WREN) instruction is entered by driving Chip Select (CS#) Low, sending the instruction

code, and then driving Chip Select (CS#) High.

Write Disable (WRDI) (04h)

The Write Disable instruction (Figure 6) resets the Write Enable Latch (WEL) bit in the Status Register to

a 0 or exit from OTP mode to normal mode. The Write Disable instruction is entered by driving Chip Select

(CS#) low, shifting the instruction code “04h” into the DI pin and then driving Chip Select (CS#) high. Note

that the WEL bit is automatically reset after Power-up and upon completion of the Write Status Register,

Page Program, Sector Erase, Block Erase (BE) and Chip Erase instructions.