Datasheet

MSL2021 [DATASHEET]

42062A–LED–02/2013

0x61 0x00 {disables EEPROM writing}

The EEPROM is now programmed with the data that are in registers 0x00 through 0x1F (the look-up table). Although not

required, now is a good time to cycle power to the MSL2021, then read registers 0x00 through 0x1F to verify that the

EEPROM was properly programmed (at power-up the EEPROM automatically programs registers 0x00 through 0x40).

Next, choose a 16-bit password and write it into the Password Registers, and into the Password Verification Registers.

For this example the password is 0xAA55:

0x68 0xAA

0x69 0x55 {writes the password into the password registers 0x68 and 0x69}

0x38 0xAA

0x38 0x55 {writes the same password into the password verification registers 0x38 and 0x39}

Now commit the password to EEPROM.

0x60 0x68 {sets the EEPROM write pointer to 0x68}

0x61 0x03 {writes the first byte of the password to the EEPROM}

Wait 5ms.

0x61 0x00 {disables EEPROM writing}

0x60 0x69 {sets the EEPROM write pointer to 0x69}

0x61 0x03 {writes the second byte of the password to the EEPROM}

Wait 5ms.

0x61 0x00 {disables EEPROM writing}

Next, set the lock bit and commit it to EEPROM.

0x3A 0x02 {sets the lock bit (bit D1) in register 0x3A}

0x60 0x3A {sets the EEPROM write pointer to 0x3A}

0x61 0x03 {writes the contents of register 0x3A to the EEPROM}

Wait 5ms.

0x61 0x00 {disables EEPROM writing}

Now cycle power to the MSL2021. All reads of the Look-Up Table now return 0x00.

To read the Table, enter the password into the password verification registers:

0x38 0xAA

0x39 0x55 {writes the password into registers 0x38 and 0x39}