The SMBALERT_MASK command can be used to prevent a warning or fault condition from asserting the SMB_ALERT# signal. Setting a MASK bit does not prevent the associated bit in the STATUS_x command from being set, but prevents the associated bit in the STATUS_x command from asserting SMB_ALERT#. The following register descriptions describe the individual mask bits available.

SMBALERT_MASK write transaction is Write Word with the following:

• CMD Address = 1Bh
• Write Data Byte Low = STATUS_x COMMAND CODE
• Write Data Byte High = STATUS_x MASK

SMBALERT_MASK read transaction is a Block Write-Block Read Process Call with the following:

• CMD Address = 1Bh
• Byte Count = 1
• Write Data Byte = STATUS_x COMMAND CODE
• Byte Count = 1
• Read Data Byte = STATUS_x MASK

Please refer to the PMBus 1.3.1 Part II specification, section 15.38 SMBALERT_MASK Command for further details on this command, and the SMBus 3.1 specification, section 6.5.8 Block Write-Block Read Process Call for further details on the process call transaction.

STATUS_BYTE added and STATUS_WORD extended per new requirement in PMBus 1.4 Section 15.38.

Writing to a mask bit marked with an X with either a 0 or 1 will not cause an IVD error in (7Eh) STATUS_CML. A bit marked with ‘X’ will default to a mask value of ‘1’ and is incapable of ever asserting SMBALERT# (most commonly these are un-supported read-only logic 0 status bit positions. Attempting to read or write a mask byte for any STATUS_X command code other than this list shall be considered as invalid data or unsupported data (IVD) error in (7Eh) STATUS_CML

For all registers, a 0b indicates that SMB_ALERT# will be asserted when the condition happens, and a 1b indicates that SMB_ALERT# will not be asserted when the condition happens.

Return to Supported PMBus Commands.

Return to Supported PMBus Commands.