Pmbus Command Summary; Pmbus Commands - Analog Devices Linear LTM 4700 User Manual

LTM4700

PMBus COMMAND SUMMARY

PMBus COMMANDS

Table 7 lists supported PMBus commands and manufac-
turer specific commands. A complete description of these
commands can be found in the "PMBus Power System Mgt
Protocol Specification – Part II – Revision 1.2". Users are
encouraged to reference this specification. Exceptions or
manufacturer specific implementations are listed in Table 7.
Floating point values listed in the "DEFAULT VALUE"
column are either Linear 16-bit Signed (PMBus Section
8.3.1) or Linear_5s_11s (PMBus Section 7.1) format,
whichever is appropriate for the command. All commands
from 0xD0 through 0xFF not listed in Table 7 are implicitly
reserved by the manufacturer. Users should avoid blind
writes within this range of commands to avoid undesired
operation of the part. All commands from 0x00 through
0xCF not listed in Table 7 are implicitly not supported by
Table 7. PMBus Commands Summary (Note: The Data Format Abbreviations are Detailed in Table 8)
CMD
COMMAND NAME CODE DESCRIPTION
PAGE 0x00
OPERATION 0x01
ON_OFF_CONFIG 0x02
CLEAR_FAULTS 0x03
PAGE_PLUS_WRITE 0x05
PAGE_PLUS_READ 0x06
WRITE_PROTECT 0x10
STORE_USER_ALL 0x15
RESTORE_USER_ALL 0x16
CAPABILITY 0x19
SMBALERT_MASK 0x1B Mask ALERT activity
VOUT_MODE 0x20
VOUT_COMMAND 0x21
VOUT_MAX 0x24
VOUT_MARGIN_HIGH 0x25
44
Provides integration with multi-page
PMBus devices.
Operating mode control. On/off, margin
high and margin low.
RUN pin and PMBus bus on/off command
configuration.
Clear any fault bits that have been set.
Write a command directly to a
specified page.
Read a command directly from a
specified page.
Level of protection provided by the device
against accidental changes.
Store user operating memory to EEPROM.
Restore user operating memory from
EEPROM.
Summary of PMBus optional communication
protocols supported by this device.
Output voltage format and exponent (2
Nominal output voltage set point.
Upper limit on the commanded output
voltage including VOUT_MARGIN_HI.
Margin high output voltage set point. Must
be greater than VOUT_COMMAND.
For more information
the manufacturer. Attempting to access non-supported or
reserved commands may result in a CML command fault
event. All output voltage settings and measurements are
based on the VOUT_MODE setting of 0x14. This translates
–12
to an exponent of 2 .
If PMBus commands are received faster than they are be-
ing processed, the part may become too busy to handle
new commands. In these circumstances the part follows
the protocols defined in the PMBus Specification v1.2,
Part II, Section 10.8.7, to communicate that it is busy.
The part includes handshaking features to eliminate busy
errors and simplify error handling software while ensur-
ing robust communication and system behavior. Please
refer to the subsection titled PMBus Communication and
Command Processing in the Applications Information
section for further details.
DATA
TYPE PAGED FORMAT UNITS NVM
R/W Byte N Reg
R/W Byte Y Reg
R/W Byte Y Reg
Send Byte N
W Block N
Block R/W N
R/W Byte N Reg
Send Byte N
Send Byte N
R Byte N Reg
Block R/W Y Reg
–12
). R Byte Y Reg
R/W Word Y
R/W Word Y
R/W Word Y
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DEFAULT
VALUE
0x00
Y 0x80
Y 0x1E
NA
Y 0x00
NA
NA
0xB0
Y See CMD
–12
2
0x14
L16 V Y 1.0
0x1000
L16 V Y 3.6
0x399A
L16 V Y 1.05
0x10CD
PAGE
76
80
80
105
76
76
77
115
115
104
105
86
87
86
87
Rev. B