Manual

MAX15301 PMBus Command Set User’s Guide
Rev 1 Page 40 of 53
MANUF_LOCK
Reference:
Maxim Specific
Lockable:
Yes
Command Code:
0xE1
Format:
Direct
Data Bytes:
2
Units:
N/A
Transfer:
Write Word
Factory Value:
0x0000
Description/Notes:
The MANUF_LOCK command contains the password value for the “manufacturer” PMBus command
security level. If the working-memory value of MANUF_PASSWD matches the working-memory value
of MANUF_LOCK, the SECURITY_LEVEL
value is set to 2, and any PMBus commands flagged in
MANUF_CONF or USER_CONF are unlocked for write operations.
Note that SECURITY_LEVEL must be set to 2 before a new value can be written to MANUF_LOCK.
The value of MANUF_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.
MANUF_PASSWD
Reference:
Maxim Specific
Lockable:
Yes
Command Code:
0xE2
Format:
Direct
Data Bytes:
2
Units:
N/A
Transfer:
Read/Write Word
Factory Value:
N/A
Description/Notes:
The MANUF_PASSWD command is the “key” or password-attempt command used to unlock the
“manufacturer” security level. If the working-memory value of MANUF_PASSWD
matches the
working-memory value of MANUF_LOCK, the SECURITY_LEVEL value is set to 2, and any PMBus
commands flagged in MANUF_CONF or USER_CONF are unlocked for write operations.
The value of MANUF_PASSWD is only retained in working memory and cannot be stored.
USER_CONF
Reference:
Maxim Specific
Lockable:
Yes
Command Code:
0xE3
Format:
Bit field
Data Bytes:
32
Units:
N/A
Transfer:
Read/Write Block
Factory Value:
0
Description/Notes:
To allow password-based write-protection on a per-command basis, the USER_CONF command has
32 data bytes, with one bit per possible PMBus command; the byte order is low to high. Each bit
position within the 32 bytes correlates to a PMBus command number from 0x00 to 0xFF. For
example:
Byte 0, bit 0: PAGE command
Byte 0, bit 1: OPERATION command
Byte 0, bit 2: ON_OFF_CONFIG command
…
Byte 6, bit 3: FREQUENCY_SWITCH command
etc…
If the bit for a particular command is set in USER_CONF, and the read-only SECURITY_LEVEL
command
is not set to level 1 by successfully sending a value of USER_PASSWD that matches the working