Datasheet

LTC2977
31
2977fa
For more information www.linear.com/LTC2977
MFR_STATUS_PLUS0 and MFR_STATUS_PLUS1 Data Contents
BIT(S) SYMBOL OPERATION
b[7:2] Reserved
b[1] Mfr_status_plus_block_
peek_failed0
Mfr_status_plus_block_
peek_failed1
Status of most recent block peek for matching host.
0: Last block peek was not aborted.
1: Last block peek was aborted due to an intervening fault log EEPROM write, MFR_FAULT_LOG_STORE
command, or standard PMBus block read of MFR_FAULT_LOG. The intervening operation is always completed
cleanly.
b[0] Mfr_status_plus_poke_
failed0
Mfr_status_plus_poke_
failed1
Status of most recent poke for matching host.
0: Last poke operation did not fail.
1: Last poke operation failed because pokes were not enabled as described in Enabling and Disabling Poke
Operations below.
MFR_STATUS_PLUS0 is at command location 0x2C, and MFR_STATUS_PLUS1 is at command location 0x2D. These correspond to reserved PMBus
command locations. These two status registers can only be read via Command Plus peeks.
Reading Fault Log Using Command Plus and Mfr_data_plus0
Write Mfr_command_plus_pointer=0xEE with Mfr_command_plus_page=0 and Mfr_command_plus_id=0.
Read data from Mfr_data_plus0; each read returns the next data word of the MFR_
FAULT_LOG command:
•
The first word read is Byte_count[15:0]=0x00FF.
• The next set of words read is the Preamble with 2 bytes packed into a word. Refer to Fault Log section for details.
• The next set of words read is the Cyclical Loop Data with 2 bytes per word. Refer to Fault Log section for details.
• Extra reads return zero.
• Interleaved PMBus word and byte commands do not interfere with an ongoing Command Plus block read.
• Interleaved PMBus block reads of MFR_FAULT_LOG will interrupt this command.
Check status to be sure the data just read was all valid:
• Write Mfr_command_plus_pointer=0x2C with Mfr_command_plus_page=0 and Mfr_command_plus_id=0.
• Read data from Mfr_data_plus0 and confirm that Mfr_status_plus_block_peek_failed0 = 0.
PMBus COMMAND DESCRIPTION