ASC7611 ETC2 [List of Unclassifed Manufacturers], ASC7611 Datasheet - Page 28

• Manufacturer Part Number: ASC7611
• Description: HARDWARE MONITOR WITH INTEGRATED FAN CONTROL
• Manufacturer: ETC2 [List of Unclassifed Manufacturers]

Register
Address
This register becomes read-only when the Ready/Lock/Start/Override register Lock bit is set. Any further attempts to write to
this register shall have no effect.
Bits [7:5] Zone/Mode
Bits [7:5] of the Fan Configuration registers associate each fan with a temperature sensor. When in Auto Fan Mode the fan
will be assigned to a zone, and its PWM duty cycle will be adjusted according to the temperature of that zone. If “Hottest”
option is selected (110), the fan will be controlled by the the hottest of zones 1, 2 or 3. To determine the “hottest zone”, the
PWM level for each zone is calculated then the zone with the higher PWM value (not temperature) is selected. When in
manual control mode, the Current PWM duty register (30-32h) become Read/Write. It is then possible to control the PWM
outputs with software by writing to these registers. When the fan is disabled (100) the corresponding PWM output should be
driven low (or high, if inverted).
Zone 1: Remote Diode 1 (processor), Zone 2: Internal Sensor, Zone 3 : Remote Diode 2
Bit [4] PWM Invert
Bit [4] inverts the PWM output. If set to 0, 100% duty cycle will yield an output that is always high. If set to 1, 100% duty
cycle will yield an output that is always low.
Bit [3] Reserved
Bit [2:0] Spin Up
Bits [2:0] specify the ‘spin up’ time for the fan. When a fan is being started from a stationary state, the PWM output is held at
100% duty cycle for the time specified in the table below before scaling to a lower speed.
© Andigilog, Inc. 2006
Register 5C-5Eh: Fan Thermal Zone Assignment and Spin-up Mode
5Ch
5Dh
5Eh
Read/
Write
R/W
R/W
R/W
Fan 1 Configuration
Fan 2 Configuration
Fan 3 Configuration
Register Name
Fan on Zone 1 auto
Fan on Zone 2 auto
Fan on Zone 3 auto
Fan always on full
Fan disabled
Fan controlled by hotter of Zones 2 or 3
Fan controlled by hottest of Zones 1, 2 or 3
Fan manually controlled (Test Mode)
(MSB)
ZON2
ZON2
ZON2
Bit 7
Table 13 Fan Spin-Up Register
0 ms
100 ms
250 ms
400 ms
700 ms
1000 ms
2000 ms
4000 ms
Fan Configuration
Spin Up Time
Table 12 Fan Zone Setting
ZON1
ZON1
ZON1
Bit 6
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ZON0
ZON0
ZON0
Bit 5
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SPIN[2:0]
Bit 4
INV
INV
INV
000
001
010
011
100
101
110
111
Bit 3
RES
RES
RES
SPIN2
SPIN2
SPIN2
Bit 2
ZON[2:0]
000
001
010
011
100
101
110
111
SPIN1
SPIN1
SPIN1
Bit 1
October 2006 - 70A05007
(LSB)
SPIN0
SPIN0
SPIN0
Bit 0
aSC7611
Default
Value
62
62
62
Lock
X
X
X