Datasheet

TPS40400
SLUS930B –APRIL 2011– REVISED OCTOBER 2011 www.ti.com
STORE_DEFAULT_CODE (13h)
The STORE_DEFAULT_CODE command instructs the PMBus core to store the contents of the programming
register whose Command Code matches the value in the data byte into memory as the new default value.
Command STORE_DEFAULT_CODE
Bit Position 7 6 5 4 3 2 1 0
Access w w w w w w w w
Function Command code
EEPROM programming faults cause the device to NACK and set the ‘cml’ bit in the STATUS_BYTE and the ‘oth’
bit in the STATUS_CML registers. It is permissible to use this command while the device is switching. Note
however that the device continues to switch but ignores all fault conditions until the internal store process has
completed.
It is permitted to use the STORE_DEFAULT_CODE command while the device is operating. However, the
device may be unresponsive during the copy operation with unpredictable, undesirable or even catastrophic
results. It is recommended to turn off the device output before issuing this command.
RESTORE_DEFAULT_CODE (14h)
The RESTORE_DEFAULT_CODE command instructs the PMBus core to overwrite the programming register
whose Command Code matches the value in the data byte, with the default value.
Command STORE_DEFAULT_CODE
Bit Position 7 6 5 4 3 2 1 0
Access w w w w w w w w
Function Command code
The RESTORE_DEFAULT_CODE command should not be used while the device is switching because the
device stops switching and restarts. During the restart, the low-side driver turns on for an extended time period
and could damage loads that are sensitive to the power rail sinking current. If this is of no concern then the
command may be used while the device is switching.
NOTE
A VIN_UV fault may be triggered when RESTORE_DEFAULT_ALL or
RESTORE_DEFAULT_CODE command is set. The firmware workaround is accomplished
by verifying that, upon completion of a RESTORE_DEFAULT_ALL or
RESTORE_DEFAULT_CODE command, the sole source asserting SMB_ALERT is
STATUS_BYTE[3] (VIN_UV). If so, issue a CLEAR_FAULTS command. Any other source
asserting SMB_ALERT under these circumstances (i.e. completion of
RESTORE_DEFAULT_ALL or RESTORE_DEFAULT_CODE) would indicate an actual
fault condition.
VOUT_MODE (20h)
Description: The PMBus specification dictates that the data word for the VOUT_MODE command is one byte
that consists of a 3-bit mode and 5-bit exponent parameter, as shown below. The 3-bit mode sets whether the
device uses the Linear or Direct modes for output voltage related commands. The 5-bit parameter sets the
exponent value for the linear data mode. The mode and exponent parameters are set and do not permit the user
to change the values.
Command VOUT_MODE
Bit Position 7 6 5 4 3 2 1 0
Access r r r r r r r r
Function Mode Exponent
Default Value 0 0 0 1 0 1 1 0
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