LTC2978CUP View Datasheet(PDF) - Linear Technology
Part Name
Description
MFG CO.
'LTC2978CUP' PDF : 64 Pages View PDF
LTC2978
PMBus Command Description
Table 2. Data Block Contents
DATA
BYTE* DESCRIPTION
Mfr_vout_peak7[7:0]
43
Mfr_vout_peak7[15:8]
44
Mfr_vout_min7[7:0]
45
Mfr_vout_min7[15:8]
46
47 bytes for preamble
Fault_log [Position_last]
47
Fault_log
48
.
.
.
Fault_log
237 Last Valid Byte
Reserved
238-254
Number of loops
(238-47)/40 = 4.8
*Note: PMBus data byte numbers start at 1 rather than 0. Position_last is the
first byte returned after BYTE COUNT = OxFF. See block read protocol.
The data returned between bytes 47 and 237 of the previous
table is interpreted using Position_last and the following
table. The key to identifying byte 47 is to locate the DATA
corresponding to POSITION = Position_last in the next
table. Subsequent bytes are identified by decrementing
the value of POSITION. For example: If Position_last = 9
then the first data returned in byte position 47 of a block
read is Read_vin[15:8] followed by Read_vin[7:0] followed
by Status_mfr of page 1. See Table 3.
Table 3. Interpreting Cyclical Loop
POSITION
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
DATA
Read_vout0[7:0]
Read_vout0[15:8]
Status_vout0
Status_mfr0
Read_vout1[7:0]
Read_vout1[15:8]
Status_vout1
Status_mfr1
Read_vin[7:0]
Read_vin[15:8]
Status_vin
Reserved
Read_vout2[7:0]
Read_vout2[15:8]
Status_vout2
Status_mfr2
Read_vout3[7:0]
Table 3. Interpreting Cyclical Loop
POSITION
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
DATA
Read_vout3[15:8]
Status_vout3
Status_mfr3
Read_temperature_1[7:0]
Read_temperature_1[15:8]
Status_temp
Reserved
Read_vout4[7:0]
Read_vout4[15:8]
Status_vout4
Status_mfr4
Read_vout5[7:0]
Read_vout5[15:8]
Status_vout5
Status_mfr5
Read_vout6[7:0]
Read_vout6[15:8]
Status_vout6
Status_mfr6
Read_vout7[7:0]
Read_vout7[15:8]
Status_vout7
Status_mfr7
Total Bytes =40
The following table fully decodes a sample fault log read
to help clarify the cyclical nature of the operation.
MFR_FAULT_LOG DATA BLOCK CONTENTS
BYTE BYTE
NUMBER NUMBER
DECIMAL HEX
0
00
1
01
2
02
3
03
4
04
PREAMBLE INFORMATION
DATA
Position_last[7:0] = 9
SharedTime[7:0]
SharedTime[15:8]
SharedTime[23:16]
SharedTime[31:24]
DESCRIPTION
Position of
Fault-Log
Pointer When
Fault Occured.
41-Bit Share-
Clock Counter
Value When
Fault Occurred.
Counter LSB
Is in 200µs
Increments.
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