EMC6D100-DK SMSC [SMSC Corporation], EMC6D100-DK Datasheet - Page 55

• Manufacturer Part Number: EMC6D100-DK
• Description: ENVIRONMENTAL MONITORING AND CONTROL DEVICE WITH AUTOMATIC FAN CAPABILITY
• Manufacturer: SMSC [SMSC Corporation]

REGISTER
Environmental Monitoring and Control Device
Datasheet
8.20
ADDRESS
SMSC EMC6D100/EMC6D101
62h
63h
FIGURE 8.2 - WHAT EMC6D100/EMC6D101 SEES WITH AND WITHOUT SPIKE SMOOTHING
The range numbers will be used to calculate the slope of the PWM ramp up. For the fractional entries, the
PWM will go on full when the temp reaches the next integer value e.g., for 3.33, PWM will be full on at (min
temp + 4).
Register 62h, 63h: Min/Off, Spike Smoothing
These registers become read only when the Lock bit is set. Any further attempts to write to these registers
shall have no effect.
The Off/Min Bits [7:5] specify whether the duty cycle will be 0% or Minimum Fan Duty when the measured
temperature falls below the Temperature LIMIT register setting (see table below). OFF1 applies to fan 1,
OFF2 applies to fan 2, and OFF3 applies to fan 3.
If the Remote1 or Remote2 pins are connected to a processor or chipset, instantaneous temperature
spikes may be sampled by the part. If these spikes are not ignored, the CPU fan (if connected to part) may
turn on prematurely and produce unpleasant noise. For this reason, any zone that is connected to a
chipset or processor should have spike smoothing enabled.
When spike smoothing is enabled, the temperature reading registers still reflect the current value of the
temperature – not the ‘smoothed out’ value.
ZN1E, ZN2E, and ZN3E enable temperature smoothing for zones 1, 2, and 3 respectively.
ZN1-2, ZN1-1, and ZN1-0 control smoothing time for Zone 1
ZN2-2, ZN2-1, and ZN2-0 control smoothing time for Zone 2
ZN3-2, ZN3-1, and ZN3-0 control smoothing time for Zone 3
READ/
WRITE
R/W
R/W
spike smoothing disabled
Temperature spike with
Spike Smoothing
Spike Smoothing
Min/Off, Zone 1
Zone 2, Zone 3
REGISTER
NAME
(MSB)
OFF3
ZN2E
BIT 7
DATASHEET
ZN2-2
BIT 6
OFF2
Page 55
ZN2-1
OFF1
BIT 5
ZN2-0
BIT 4
RES
spike smoothing enabled
Spike 'smoothed' with
ZN1E
ZN3E
BIT 3
ZN1-2
ZN3-2
BIT 2
ZN1-1
ZN3-1
BIT 1
ZN1-0
ZN3-0
(LSB)
BIT 0
Rev. 09-09-04
DEFAULT
VALUE
00h
00h