Mfr_Fault_Propagate_Ltc3882-1 - Linear Technology Analog Devices LTC3882-1 Datasheet

PMBus COMMAND DETAILS
Figure 51 shows an example of the Write Word format used to set an ALERT mask, in this case without PEC. The bits
in the mask byte align with bits in the specified status register. For example, if the STATUS_TEMPERATURE command
code is sent in the first data byte, and the mask byte contains 0x40, then a subsequent External Overtemperature Warn-
ing would still set bit 6 of STATUS_TEMPERATURE but not assert ALERT. All other supported STATUS_TEMPERATURE
bits would continue to assert ALERT if set.
Figure 52 shows an example of the Block Write – Block Read Process Call protocol used to read back the present state
of any supported status register, again without PEC.
SMBALERT_MASK cannot be applied to STATUS_BYTE, STATUS_WORD, MFR_COMMON or MFR_PADS_LTC3882-1.
Factory default masking for applicable status registers is shown below. Providing an unsupported command code to
SMBALERT_MASK will generate a CML for Invalid/Unsupported Data.
SMBALERT_MASK Default Setting: (Refer Also to Figure 2)
STATUS RESISTER ALERT Mask Value MASKED BITS
STATUS_VOUT
STATUS_IOUT
STATUS_TEMPERATURE
STATUS_CML
STATUS_INPUT
STATUS_MFR_SPECIFIC

MFR_FAULT_PROPAGATE_LTC3882-1

The MFR_FAULT_PROPAGATE_LTC3882-1 command determines events that cause FAULT to be asserted. Setting a
bit in this register to a one allows the specified condition to assert the FAULT output for that channel. FAULT is not as-
serted by a fault, even if set to propagate, if that FAULT_RESPONSE is set to Ignore. The state of SMBLALERT_MASK
does not affect FAULT propagation.
(Fault Response and Communication)
1 7 1 1
SLAVE SMBALERT_MASK
S W A
ADDRESS COMMAND CODE
Figure 51. Example of Setting SMBALERT_MASK
1 7 1 1
SLAVE SMBALERT_MASK
S W A
ADDRESS COMMAND CODE
1 7 1 1
SLAVE
Sr R A
ADDRESS
Figure 52. Example of Reading SMBALERT_MASK
0x00 None
0x00 None
0x00 None
0x00 None
0x00 None
0x11 Bit 4 (internal PLL unlocked), bit 0 (FAULT low)
For more information
8 1 8 1
STATUS_x
A A
COMMAND CODE
8 1 8 1
BLOCK COUNT
A A
(= 1)
8 1 8
BLOCK COUNT
A MASK BYTE
(= 1)
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LTC3882-1
8 1 1
MASK BYTE A P
38821 F51
8 1
STATUS_x
A ...
COMMAND CODE
1 1
NA P
38821 F52
Rev A
99