Motherboard Monitor configuration

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Short version:

Has anyone succeeded in adding custom voltages to MBM's output, either
to the screen or to a log file?

Long version:

Recently I've been experimenting with MBM5 and an ECS L7S7A2
mainboard. The board uses an ITE IT8705 multi-IO chip which
incorporates voltage, temperature, and fan monitoring. AMIBIOS
Hardware Monitor displays the following parameters:

CPU core volts
DDR memory volts
+3.3V
+5V
+12V
SB +3.3V
SB +5V

CHS fan speed
CPU fan speed

Sys Temp
CPU Temp

MBM5 originally showed nothing for system temperature. This was
corrected by assigning sensor 3 to IT8705F-2.

MBM reports bogus values for -12V and -5V. This is because the IT8705
chip does not monitor these voltages (ECS have departed from standard
practice). Instead it detects +5VSB and +3.3VSB at registers $27 and
$25, respectively. Editing the "voltage custom.ini" file allows MBM to
detect the latter voltages, but unfortunately they are still wrongly
identified as -12V and -5V. I attempted to add extra voltages to MBM's
output but could not get it to behave as documented. Has anyone
succeeded in doing this?

This is what I did. From the Voltages menu I selected the Voltage 8
and Voltage 9 sensors and configured them as "MBM Fixed" (later I also
tried "Custom" without success). I then added the following block to
"voltage custom.ini".

[Custom]
V1=$20*0.016 /* CPU core
V2=$21*0.016 /* DDR (2.5V)
V3=$22*0.016 /* +3.3
V4=$23*0.016*1.68 /* +5V
V5=$24*0.016*4 /* +12V
V6=0
V7=0
V8=$27*0.016*1.68 /* +5VSB
V9=$25*0.016 /* +3.3VSB
V10=$28*0.016 /* Vbat

After restarting MBM, the -5V and -12V parameters were displayed as 0,
but V8,9,10 were not there. I enabled the log but did not find the new
voltages there either. This is how I have the voltage monitor
configured at present:

[Custom]
V1=$20*0.016 /* CPU core
V2=$21*0.016 /* DDR (2.5V)
V3=$22*0.016 /* +3.3
V4=$23*0.016*1.68 /* +5V
V5=$24*0.016*4 /* +12V
V6=$27*0.016*1.68 /* +5VSB
V7=$25*0.016 /* +3.3VSB

If I change the V7 line to ...

V7=$28*0.016 /* Vbat

.... MBM will display the voltage of the lithium backup battery
(3.06V).

FWIW, doing the same for register $26 displays 0.98V.

Before starting on MBM, I found it instructive to observe the BIOS h/w
monitor screen. I noticed that many of the voltages varied over time.
The smaller ones varied in 0.016V increments, while the +12V rail
moved in 0.064V steps, and the 5V rails in 0.027V increments. This is
consistent with an 8-bit A/D converter with a Vref of 4.096V. Each
count is equal to 4.096 / 256 = 0.016V. The +12V input is divided by
4, hence each count is 4 x 0.016 = 0.064V. The 5V rails are divided by
1.68 which results in steps of 1.68 x 0.016 = 0.0269V. All these
divisors can be seen in the voltage.ini file above.


- Franc Zabkar
--
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