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Security_level – Maxim Integrated MAX15301 PMBus Command Set User Manual

Page 42

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MAX15301 PMBus Command Set User’s Guide

Rev 1

Page 42 of 53

SECURITY_LEVEL

Reference:

Maxim Specific

Lockable:

N/A

Command Code:

0xE6

Format:

Direct

Data Bytes:

1

Units:

N/A

Transfer:

Read Byte

Factory Value:

0x00

Description/Notes:

The MAX15301 provides two levels of password protection for all writeable PMBus commands, on a
per-command basis. The SECURITY_LEVEL command value shows the present security level as follows:

SECURITY_LEVEL

Description

0x00

No write access to commands locked by

USER_CONF

or

MANUF_CONF

0x01

Write access granted to commands locked by USER_CONF

0x02

Write access granted to commands locked by MANUF_CONF and USER_CONF

Note that SECURITY_LEVEL is 0 until a value is written to

USER_PASSWD

or

MANUF_PASSWD

that

matches the working-memory value of

USER_LOCK

or

MANUF_LOCK

respectively.

When the working-memory value of USER_LOCK is written to USER_PASSWD, SECURITY_LEVEL is set
to 1.

When the working-memory value of MANUF_LOCK is written to MANUF_PASSWD, SECURITY_LEVEL is
set to 2.

Writing a “mismatched” (or wrong) value of USER_PASSWD or MANUF_PASSWD causes
SECURITY_LEVEL to reset to 0.

The values of USER_LOCK and USER_CONF can only be changed when SECURITY_LEVEL is 1 or 2.

The values of MANUF_LOCK and MANUF_CONF can only be changed when SECURITY_LEVEL is 2.