Pmbus Command Summary - Analog Devices LT7170 Reference Manual

Reference Manual

PMBUS COMMAND SUMMARY

Table 1 lists supported PMBus commands and manufacturer specific commands. A complete description of the included PMBus commands
is found in the PMBus Power System Management Protocol Specification. Floating point values listed in the default value column are
half-precision IEEE floating point numbers. All commands from 0xC0 through 0xFF not listed in
manufacturer. Users must avoid blind writes within this range of commands to avoid undesired operation of the LT7170/LT7170-1. All
commands from 0x00 through 0xBF not listed in
reserved commands results in a CML command fault event.
The LT7170/LT7170-1 contain additional manufacturer reserved commands not listed in
operation of the IC. However, the contents and meaning of these commands can change without notice.
Some of the unpublished commands are read only and generate a CML Bit 6 fault if written. Writing to commands not published in
not permitted.
Table 1. Supported PMBus and MFR Commands
2
Command Name
PAGE
OPERATION
ON_OFF_CONFIG
CLEAR_FAULTS
PAGE_PLUS_WRITE
PAGE_PLUS_READ
ZONE_CONFIG
ZONE_ACTIVE
WRITE_PROTECT
STORE_USER_ALL
RESTORE_USER_ALL
CAPABILITY
QUERY
SMBALERT_MASK
VOUT_MODE
VOUT_COMMAND
VOUT_MAX
VOUT_MARGIN_HIGH
VOUT_MARGIN_LOW
VOUT_TRANSITION_RATE
analog.com
Table 1 are implicitly not supported by the manufacturer. Attempting to access unsupported or
1
Command
Code Description
0x00 Provides integration with multipage PMBUS devices.
0x01 Operating mode control. On/off, margin high, and
margin low.
0x02 RUN pin and PMBus bus on/off command
configuration.
0x03 Clears any fault bits that have been set.
0x05 Writes a command directly to a specified page.
0x06 Reads a command directly from a specified page.
0x07 Assigns current page to specified zone number for
ZONE_WRITE operations.
0x08 Selects active zone for ZONE_WRITE operations.
0x10 Level of protection provided by the device against
accidental changes.
0x15 Stores user operating memory to NVM. Can be written
three times.
0x16 Restores user operating memory from NVM.
0x19 Summary of PMBus optional communication protocols
supported by this device.
0x1A Asks if a given command is supported, and what data
formats are supported.
0x1B Masks ALERT activity.
0x20 Output voltage format and exponent.
0x21 Nominal output voltage set point.
0x24 Upper limit on the commanded output voltage.
0x25 Margin high output voltage set point.
0x26 Margin low output voltage set point.
0x27 Rates the output changes when V
a new value.
LT7170/LT7170-1
Table 1 are implicitly reserved by the
Table 1. Reading these commands is harmless to the
Data
Type Format
R/W Register
byte
R/W Register
byte
R/W Register
byte
Send
byte
W
block
Block
R/W
W Register
word
W Register
word
R/W Register
byte
Send
byte
Send
byte
R byte Register
Block Register
R/W
Block Register
R/W
R byte Register
R/W IEEE
word
R/W IEEE
word
R/W IEEE
word
R/W IEEE
word
commanded to R/W IEEE
OUT
word
Table 1 is
3
Unit NVM Default Value
No 0x00
Yes 0x80
Yes 0x1E
Yes 0xFEFE
No 0xFEFE
Yes 0x00
No 0xD8
No
Yes
No 0x60
V Yes 0.5, 0x3800
V Yes 0.537, 0x384C
V Yes 0.525, 0x3833
V Yes 0.475, 0x3799
V/ms Yes 0.25, 0x3400
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