Instruction Manual

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MAX15303 PMBus Command Set User’s Guide

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USER_CONF

memory value of USER_LOCK, then the MAX15303 will ignore attempts to write data to that

command.

Note that setting a bit for a read-only PMBus command or send-byte PMBus command has no effect,

regardless of SECURITY_LEVEL. Likewise, read operations for any PMBus command are never blocked

on the basis of USER_CONF and SECURITY_LEVEL.

The 32 data bytes for USER_CONF are saved in flash memory as a unique, single instance (i.e., not as

part of the USER, DEFAULT, or MAXIM PMBus command stores.) The data is written to flash every

time the USER_CONF command data is written to the MAX15303.

Wait

at least 350ms for execution after sending the USER_CONF command before sending additional

PMBus commands.

USER_LOCK

Reference:

Maxim Specific

Lockable:

Yes

Command Code:

0xE4

Format:

Direct

Data Bytes:

Units:

N/A

Transfer:

Read Word

Factory Value:

0x0000

Description/Notes:

The USER_LOCK command contains the password value for the “user” PMBus command security

level. If the working-memory value of USER_PASSWD matches the working-

memory value of

USER_LOCK, the SECURITY_LEVEL value is set to 1, and any PMBus commands flagged in USER_CONF

are unlocked for write operations.

Note that SECURITY_LEVEL must be set to 1 before a new value can be written to USER_LOCK.

The value of USER_LOCK can be stored in both the USER and DEFAULT nonvolatile PMBus memory

with separate and distinct values –

this should be taken into account when setting up command

security.

USER_PASSWD