Functional Description (Continued)
12.8 Fan Divisor Register/RST_OUT/OS — Address 05h
<
>
<
>
<
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Power on – 7:4 is 0101, and 3:0 is mapped to VID 3:0
Bit
Name
Read/Write
Description
0
FAN1 Mode
Select
Read/Write
A one selects the level sensitive input mode while a zero selects Fan count mode
for the FAN1 input pin.
1
FAN2 Mode
Select
Read/Write
Read/Write
A one selects the level sensitive input mode while a zero selects Fan count mode
for the FAN2 input pin.
2-3
FAN1 RPM
Control
FAN1 Speed Control.
=
=
=
=
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<
<
<
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>
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3:2
3:2
3:2
3:2
00 - divide by 1;
01 - divide by 2;
10 - divide by 4;
11 - divide by 8.
=
1 selects and active-low input (An interrupt
> <
2
If level sensitive input is selected:
=
> <
2
will be generated if the FAN2 input is Low),
0 selects an active-high input (an
interrupt will be generated if the FAN2 input is High).
4-5
FAN2 RPM
Control
Read/Write
FAN2 Speed Control.
=
=
=
=
<
<
<
<
>
>
>
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5:4
5:4
5:4
5:4
00 - divide by 1;
01 - divide by 2;
10 - divide by 4;
11 - divide by 8.
=
< >
If level sensitive input is selected:
will be generated if the FAN2 input is Low),
interrupt will be generated if the FAN2 input is High).
2
1 selects and active-low input (An interrupt
=
< >
2
0 selects an active-high input (an
6
7
OS pin enable
RST enable
Read/Write
Read/Write
A one enables OS mode on the RST_OUT/OS output pin, while Bit 7 of this register
is set to zero. If bits 6 and 7 of this register are set to zero the RST_OUT/OS pin is
disabled.
A one sets the RST_OUT/OS pin in the RST mode. In the RST mode, bit 7 of the
Fan Divisor/RST_OUT/OS Register has to be set to one. If bits 6 and 7 of this
register are set to zero the RST_OUT/OS pin is disabled.
12.9 OS Configuration/Temperature Resolution Register — Address 06h
=
>
<
Power on default Serial Bus address 7:0
0000 0001 binary
Bit
Name
Read/Write
Description
0
OS status
Read only
Status of the OS.This bit mirrors the state of the RST_OUT/OS pin when in the OS
mode.
1
2
3
OS Polarity
Read/Write
Read/Write
Read/Write
A zero selects OS to be active-low, while a one selects OS to be active high. OS is
an open-drain output.
OS mode select
A one selects the one time interrupt mode for OS, while a zero selects comparator
mode for OS. (See in Section 7.0)
Temperature
Resolution
Control
A zero selects the default 8-bit plus sign resolution temperature conversions while a
one selects 11-bit plus sign resolution temperature conversions. 8-bit plus sign
conversions time is approximately 100 ms, while 11-bit plus sign conversion time is
approximately 2 seconds.
=
Temp
< >
4
4-7
Temp [3:0]
Read/Write
The lower nibble (4 LSBs) of the 11-bit plus sign temperature data.
=
=
=
< >
5
< >
6
< >
Temp [2], 7
[0] (nibble LSB, 0.0625˚C),
Temp [1],
Temp 3
=
< >
7
(nibble MSB, 0.5˚C). For 8-bit plus sign temperature resolution,
Temp [0]
<
>
(LSB, 0.5˚C) while 4:6 are undefined.
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