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© Andigilog, Inc. 2006
www.andigilog.com
October 2006 - 70A06010
aSC7621
Temperature
Fan Temp Limit
(2’s Complement)
+50°C
0011
0010
+25°C
0001
1001
0°C
0000
0000
-50°C
1100
1110
-127°C
1000
0001
Table 26 Fan Temperature Limit Register -
8-Bit Two’s Complement
Register 6A-6Ch: Temperature Limit
Register
Address
Read/
Write
Register
Name
Bit 7
(MSB)
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
(LSB)
Default
Value
Lock
6Ah
R/W
Zone 1 Temp
Absolute Limit
7
6
5
4
3
2
1
0
64
X
6Bh
R/W
Zone 2 Temp
Absolute Limit
7
6
5
4
3
2
1
0
64
X
6Ch
R/W
Zone 3 Temp
Absolute Limit
7
6
5
4
3
2
1
0
64
X
3Dh
R/W
Zone 4 Temp
Absolute Limit
7
6
5
4
3
2
1
0
00
X
In the Auto Fan mode, if a zone exceeds the temperature set in the Absolute Temperature Limit register, all of the PWM
outputs will increase its duty cycle to 100%. This is a safety feature that attempts to cool the system if there is a potentially
catastrophic thermal event. If set to 80h (-128
°C), the feature is disabled. Default = 100 C = 64h. The PWM will remain at
100% until the assigned Temperature Zone falls below the Absolute Temp Limit for that zone by an amount equal to the
hysteresis value for that zone.
These registers become read-only when the Ready/Lock/Start/Override register Lock bit is set. Any further attempts to write
to these registers shall have no effect.
Temperature
Absolute Limit
(2’s Complement)
>127°C
0111
1111
+127°C
0111
1111
+125°C
0111
1101
+100°C (default)
0110
0100
+50°C
0011
0010
+25°C
0001
1001
0°C
0000
0000
-50°C
1100
1110
-127°C
1000
0001
-128°C (Disable)
1000
0000
Table 27 Absolute Temperature Limit Register -
8-Bit Two’s Complement