Table of Contents
Advertisement
LTM4700
PMBus COMMAND DETAILS
would still set bit 6 of STATUS_TEMPERATURE but not assert ALERT. All other supported STATUS_TEMPERATURE
bits would continue to assert ALERT if set.
Figure 53 shows an example of the Block Write – Block Read Process Call protocol used to read back the present state
of any supported status register, again without PEC.
SMBALERT_MASK cannot be applied to STATUS_BYTE, STATUS_WORD, MFR_COMMON or MFR_PADS_LTM4700.
Factory default masking for applicable status registers is shown below. Providing an unsupported command code to
SMBALERT_MASK will generate a CML for Invalid/Unsupported Data.
SMBALERT_MASK Default Setting: (Refer Also to Figure 2)
STATUS RESISTER
ALERT Mask Value MASKED BITS
STATUS_VOUT
STATUS_IOUT
STATUS_TEMPERATURE
STATUS_CML
STATUS_INPUT
STATUS_MFR_SPECIFIC
MFR_CLEAR_PEAKS
The MFR_CLEAR_PEAKS command clears the MFR_*_PEAK data values. A MFR_RESET command will also clear the
MFR_*_PEAK data values.
This write-only command has no data bytes.
STATUS_BYTE
The STATUS_BYTE command returns one byte of information with a summary of the most critical faults. This is the
lower byte of the status word.
106
0x00
None
0x00
None
0x00
None
0x00
None
0x00
None
0x11
Bit 4 (internal PLL unlocked), bit 0 (FAULT pulled low by external device)
1
7
1
1
SLAVE
SMBALERT_MASK
S
W A
ADDRESS
COMMAND CODE
Figure 53. Example of Writing SMBALERT_MASK
1
7
1
1
SLAVE
SMBALERT_MASK
S
W A
ADDRESS
COMMAND CODE
1
7
1
1
SLAVE
Sr
R
A
ADDRESS
Figure 54. Example of Reading SMBALERT_MASK
For more information
8
1
8
1
STATUS_x
A
A
COMMAND CODE
8
1
8
1
BLOCK COUNT
A
A
(= 1)
8
1
8
BLOCK COUNT
A
MASK BYTE
(= 1)
www.analog.com
8
1
1
MASK BYTE
A
P
4700 F53
8
1
STATUS_x
A
...
COMMAND CODE
1
1
NA P
4700 F54
Rev. B
Advertisement
Table of Contents
