Datasheet

LTC2978A
57
2978afa
For more information www.linear.com/LTC2978A
MFR_FAULT_LOG
Read only. This 2040-bit (255 byte) data block contains
a copy of the RAM buffer fault log. The RAM buffer is
continuously updated after each ADC conversion as long
as Mfr_fault_log_status_ram is clear.
With Mfr_config_all_fault_log_enable = 1 and Mfr_fault_
log_status_eeprom = 0, the RAM buffer is transferred to
EEPROM whenever an LTC2978A fault causes a channel
to latch off or a MFR_FAULT_LOG_STORE command is
received.
Mfr_fault_log_status_eeprom is set high after the RAM
buffer is transferred to EEPROM and not cleared until
a MFR_FAULT_LOG_CLEAR is received, even if the
LTC2978A is reset or powered down. Fault log EEPROM
transfers are not initiated as a result of Status_mfr_dis
-
charge events.
During a MFR_FAULT_LOG read, data is returned as defined
by the following table. The fault log data is partitioned
into two sections. The first section is referred to as the
preamble and contains the Position-last pointer, time
information and peak and minimum values. The second
section contains a chronological record of telemetry and
requires Position-last for proper interpretation. The fault
log stores approximately 0.5 seconds
of telemetry. To
prevent
timeouts during block reads, it is recommended
that Mfr_config_all_longer_pmbus_timeout be set to 1.
Table 2. Data Block Contents
DATA BYTE* DESCRIPTION
Position_last[7:0] 0 Position of fault log pointer
when fault occurred.
SharedTime[7:0] 1 41-bit share-clock counter
value when fault occurred.
Counter LSB is in 200µs
increments. This counter is
cleared at power-up or after
the LTC2978A is reset
SharedTime[15:8] 2
SharedTime[23:16] 3
SharedTime[31:24] 4
SharedTime[39:32] 5
SharedTime[40] 6
Mfr_vout_peak0[7:0] 7
Mfr_vout_peak0[15:8] 8
Mfr_vout_min0[7:0] 9
Mfr_vout_min0[15:8] 10
Mfr_vout_peak1[7:0] 11
Mfr_vout_peak1[15:8] 12
Mfr_vout_min1[7:0] 13
Mfr_vout_min1[15:8] 14
Mfr_vin_peak[7:0] 15
Mfr_vin_peak[15:8] 16
Mfr_vin_min[7:0] 17
Mfr_vin_min[15:8] 18
Mfr_vout_peak2[7:0] 19
Mfr_vout_peak2[15:8] 20
Mfr_vout_min2[7:0] 21
Mfr_vout_min2[15:8] 22
Mfr_vout_peak3[7:0] 23
Mfr_vout_peak3[15:8] 24
Mfr_vout_min3[7:0] 25
Mfr_vout_min3[15:8] 26
Mfr_temp_peak[7:0] 27
Mfr_temp_peak[15:8] 28
Mfr_ temp_min[7:0] 29
Mfr_ temp_min[15:8] 30
Mfr_vout_peak4[7:0] 31
Mfr_vout_peak4[15:8] 32
Mfr_vout_min4[7:0] 33
Mfr_vout_min4[15:8] 34
Mfr_vout_peak5[7:0] 35
Mfr_vout_peak5[15:8] 36
Mfr_vout_min5[7:0] 37
Mfr_vout_min5[15:8] 38
Mfr_vout_peak6[7:0] 39
Mfr_vout_peak6[15:8] 40
Mfr_vout_min6[7:0] 41
Mfr_vout_min6[15:8] 42
PMBus COMMAND DESCRIPTION