Datasheet

MAX34451 PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
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Figure 11. MFR_NV_FAULT_LOG
Alarm Output Functionality
Any of the GPOn pins can be configured to output
the alarm signals. See the MFR_PWM_CONFIG and
MFR_PSEN_CONFIG commands for details. When an
undervoltage or overvoltage/overcurrent alarm is occur-
ring, the output remains asserted as long as the alarm
continues. When a sequencing fault occurs, the alarm
pin remains asserted until either a CLEAR_FAULTS
command is received, or a master power control off input
isreceivedwitheithertheOPERATIONcommandorthe
CONTROLnpins.
MFR_FAULT_RETRY (DAh)
TheMFR_FAULT_RETRYcommandsetsthedelaytime
between a fault occurring that results in a power supply
being shut down for retry and the power supply restart-
ing. This command value is used for all fault responses
that require delay retry. The retry timer starts when the
fault occurs. If the faulty channel has been configured to
assert one or more FAULTn pins, the FAULTn pins are
asserted until the retry timer expires, and then they are
allowed to deassert as long as no enabled faults are still
present and no other channel sharing the same FAULTn
pinshavenotalsoasserted.MFR_FAULT_RETRYshould
be configured with a value larger than the largest system
TOFF_DELAY.The2databytesareinDIRECTformat.
MFR_NV_FAULT_LOG (DCh)
Each time the MFR_NV_FAULT_LOG command is
executed, the device returns a block of 255 bytes
containing one of the 15 nonvolatile fault logs. The
MFR_NV_FAULT_LOG commandmust be executed 15
times to dump the complete nonvolatile fault log. If the
returnedfaultlogisallFFs(exceptbytes0and1),this
indicates that this fault log has not been written by the
device. As the device is operating, it is reading the latest
operating conditions for voltage, current, and temperature
and updating the status registers. All this information
isstoredinon-board RAM. Whenafaultisdetected (if
so enabled in MFR_FAULT_RESPONSE), the device
automatically logs this information to one of the 15 non-
volatilefaultlogs.After15faultshavebeenwritten,bit0
ofSTATUS_CMLissetandthedevicecanbeconfigured
(withtheNV_LOG_OVERWRITEbitinMFR_NV_LOG_
CONFIG) to either stop writing additional fault logs or
write over the oldest data. The host can clear the fault
logbysettingtheCLEAR_NV_FAULT_LOGbitinMFR_
NV_LOG_CONFIG.Ifapowersupplyisnotenabledto
measure voltage, current, or if a temperature sensor is
disabled,theassociatedfaultlogpositionreturns0000h
(seeFigure11).
RAM
FAULT_LOG_INDEX
FAULT_LOG_COUNT
MFR_TIME_COUNT
STATUS_WORD
STATUS_VOUT/STATUS_IOUT
STATUS_MFR_SPECIFIC
STATUS_CML
STATUS_TEMPERATURE
READ_VOUT/READ_IOUT (3 READINGS)
READ_TEMPERATURE_1
MFR_VOUT_PEAK/MFR_IOUT_PEAK
MFR_TEMPERATURE_PEAK
MFR_VOUT_MIN
EACH FAULT IS WRITTEN
INTO THE NEXT FAULT LOG
EACH COMMAND READ
ACCESSES THE NEXT FAULT LOG
FAULT
OCCURRENCE
MFR _NV_FAULT_LOG
FAULT LOG INDEX 0
(255 BYTES)
FAULT LOG INDEX 1
(255 BYTES)
FAULT LOG INDEX 2
(255 BYTES)
FAULT LOG INDEX 14
(255 BYTES)
FLASH