M24M02E-F datasheet(29/54 Pages) STMICROELECTRONICS

Part #	M24M02E-F

Description	2-Mbit serial I²C bus EEPROM with configurable device address, software write protection registers, and preprogrammed device address

PDF	54 Pages

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Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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29 / 54 page

6.5.5

Read lock status on identification page

The lock/unlock status of the identification page can be checked by transmitting a specific truncated command.

Following a start condition the bus controller sends a device select code with the R/W bit (RW) set to 0. The

device acknowledges this and waits for the address bytes where the identification page is located. The device

responds to each address byte with an acknowledge bit, and then waits for the data byte. See in Table 9,

Table 10, and Table 11 how to address the identification page.

The device returns an acknowledge bit after the data byte if the identification page is unlocked (unlock status) as

shown in Figure 22, otherwise a NoAck bit as shown in Figure 23, if the identification page is locked (lock status).

Right after this, it is recommended to transmit to the device a start condition followed by a stop condition, so that:

•

Start: the truncated command is not executed because the start condition resets the device internal logic

•

Stop: the device is then set back into standby mode by the stop condition

Figure 22. Read lock status (identification page unlocked)

Dev sel

Byte addr

Data in

ACK

Figure 23. Read lock status (identification page locked)

Dev sel

Byte addr

Data in

ACK

NO ACK

M24M02E-F

Instructions

DS14157 - Rev 2

page 29/54

M24M02E-F Datasheet(PDF) 29 Page - STMicroelectronics