Datasheet

LTC2977
43
2977fa
For more information www.linear.com/LTC2977
STATUS_CML
The STATUS_CML command returns the summary of the communication, memory and logic faults or warnings which
have occurred, as shown in the following table:
STATUS_CML Data Contents
BIT(S) SYMBOL OPERATION
b[7] Status_cml_cmd_fault Illegal or unsupported command fault has occurred.
b[6] Status_cml_data_fault Illegal or unsupported data received.
b[5] Status_cml_pec_fault A PEC fault has occurred. Note: PEC checking is always active in the LTC2977. Any extra byte received before a
STOP will set Status_cml_pec_fault unless the extra byte is a matching PEC byte.
b[4] Status_cml_memory_fault A fault has occurred in the EEPROM.
b[3] Status_cml_processor_fault Not supported, always returns 0.
b[2] Reserved Reserved, always returns 0.
b[1] Status_cml_pmbus_fault A communication fault other than ones listed in this table has occurred. This is a catch all category for illegally
formed I
2
C/SMBus commands (Example: An address byte with read =1 received immediately after a START).
b[0] Status_cml_unknown_fault Not supported, always returns 0.
STATUS_MFR_SPECIFIC
The STATUS_MFR_SPECIFIC command returns manufacturer specific status flags. Bits marked CHANNEL=All are
not paged. Bits marked STICKY=Yes stay set until a CLEAR_FAULTS is issued or the channel is commanded on by
the user. Bits marked ALERT=Yes pull ALERTB low when the bit is set. Bits marked OFF=Yes indicate that the event
can be configured elsewhere to turn the channel off. See MFR_STATUS_2 on page 62 for additional bits related to
manufacturer specific status.
STATUS_MFR_SPECIFIC Data Contents
BIT(S) SYMBOL OPERATION CHANNEL STICKY ALERT OFF
b[7] Status_mfr_discharge A V
OUT
discharge fault occurred while attempting to enter the ON
state
Current Page Yes Yes Yes
b[6] Status_mfr_fault1_in This channel attempted to turn on while the FAULTBz1 pin
was asserted low, or this channel has shut down at least once
in response to a FAULTBz1 pin asserting low since the last
CONTROLn pin toggle, OPERATION command ON/OFF cycle or
CLEAR_FAULTS command.
Current Page Yes Yes Yes
b[5] Status_mfr_fault0_in This channel attempted to turn on while the FAULTBz0 pin
was asserted low, or this channel has shut down at least once
in response to a FAULTBz0 pin asserting low since the last
CONTROLn pin toggle, OPERATION command ON/OFF cycle or
CLEAR_FAULTS command.
Current Page Yes Yes Yes
b[4] Status_mfr_servo_target_reached Servo target has been reached. Current Page No No No
b[3] Status_mfr_dac_connected DAC is connected and driving V
DACP
pin. Current Page No No No
b[2] Status_mfr_dac_saturated A previous servo operation terminated with maximum or
minimum DAC value.
Current Page Yes No No
b[1] Status_mfr_vinen_faulted_off V
IN_EN
has been deasserted due to a V
OUT
fault. All No No No
b[0] Status_mfr_watchdog_fault
A watchdog fault has occurred. All Yes Yes No
PMBus COMMAND DESCRIPTION