EMC6D102 SMSC Corporation, EMC6D102 Datasheet - Page 59

• Manufacturer Part Number: EMC6D102
• Description: Fan Control Device
• Manufacturer: SMSC Corporation

Fan Control Device with Hardware Monitoring and Acoustic Noise Reduction Features
Datasheet
SMSC EMC6D102
7.2.16
Register
Address
5Ch
5Dh
5Eh
Read/
Write
R/W
R/W
R/W
The fan tachometer will not cause a bit to be set in the interrupt status register if the current value in
the associated Current PWM Duty registers is 00h or if the PWM is disabled via the PWM
Configuration Register.
Interrupts will never be generated for a fan if its tachometer minimum is set to FFFFh.
Registers 5C-5Eh: PWM Configuration
These registers become read only when the Lock bit is set. Any further attempts to write to these
registers shall have no effect.
Bits [7:5] Zone/Mode
Bits [7:5] of the PWM Configuration registers associate each PWM with a temperature sensor.
Note:
When in Auto Fan Mode, the PWM 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 (101 or 110), the
PWM will be controlled by the hottest of zones 2 and 3, or of zones 1, 2, and 3. If one of these
options is selected, the PWM is controlled by the limits and parameters for the zone that requires
the highest PWM duty cycle, as computed by the auto fan algorithm.
When in manual control mode, the PWMx Current Duty Cycle Registers (30h-32h) become
Read/Write. It is then possible to control the PWM outputs with software by writing to these
registers. See PWMx Current Duty Cycle Registers description.
When the fan is disabled (100) the corresponding PWM output is driven low (or high, if inverted).
When the fan is Full On (011) the corresponding PWM output is driven high (or low, if inverted).
Zone 1 is controlled by Remote Diode 1 Temp Reading register
Zone 2 is controlled by Internal Temp Reading Register
Zone 3 is controlled by Remote Diode 2 Temp Reading register
PWM 1 Configuration
PWM 2 Configuration
PWM 3 Configuration
Register Name
ZON[7:5]
000
001
010
011
100
101
110
111
Fan on zone 1 auto
Fan on zone 2 auto
Fan on zone 3 auto
Fan always on full
Fan disabled
Fan controlled by hottest of zones 2,3
Fan controlled by hottest of zones 1,2,3
Fan manually controlled
Table 7.7 Fan Zone Setting
(MSb)
ZON2
ZON2
ZON2
Bit 7
DATASHEET
PWM CONFIGURATION
ZON1
ZON1
ZON1
Bit 6
59
ZON0
ZON0
ZON0
Bit 5
Bit 4
INV
INV
INV
Bit 3
RES
RES
RES
SPIN2
SPIN2
SPIN2
Bit 2
SPIN1
SPIN1
SPIN1
Bit 1
Revision 0.4 (06-15-06)
SPIN0
SPIN0
SPIN0
(LSb)
Bit 0
Default
Value
62h
62h
62h