EMC6D103-CK SMSC [SMSC Corporation], EMC6D103-CK Datasheet - Page 70

• Manufacturer Part Number: EMC6D103-CK
• Description: FAN CONTROL DEVICE WITH HIGH FREQUENCY PWM
• Manufacturer: SMSC [SMSC Corporation]

Revision 0.4 (04-04-05)
8.2.18
Register
Address
64h
65h
66h
RRX-[2:0]
000
001
010
100
101
011
110
111
MINIMUM PWM DUTY
Read/
Write
R/W
R/W
R/W
Registers 64-66h: Minimum PWM Duty Cycle
These registers become read only when the Lock bit is set. Any further attempts to write to these
registers shall have no effect.
These registers specify the minimum duty cycle that the PWM will output when the measured
temperature reaches the Temperature LIMIT register setting in Auto Fan Control Mode.
100%
25%
50%
0%
.
.
.
.
.
.
.
.
.
100% DUTY CYCLE)
PWM RAMP TIME
(TIME FROM 33%
DUTY CYCLE TO
PWM1 Minimum Duty Cycle
PWM2 Minimum Duty Cycle
PWM3 Minimum Duty Cycle
Table 8.32 Registers 64-66h: Minimum PWM Duty Cycle
(SEC)
Register Name
17.6
11.8
7.0
4.4
3.0
1.6
0.8
35
Table 8.33 PWM Duty vs. Register Setting
Fan Control Device with High Frequency PWM Support and Hardware Monitoring Features
Table 8.31 PWM Ramp Rate Control
100% DUTY CYCLE)
VALUE (DECIMAL)
PWM RAMP TIME
DATASHEET
DUTY CYCLE TO
(TIME FROM 0%
(MSb)
Bit 7
7
7
7
17.595
10.455
(SEC)
52.53
26.52
1.275
128
255
6.63
4.59
2.55
64
70
0
.
.
.
.
.
.
.
.
.
Bit 6
6
6
6
Bit 5
5
5
5
TIME PER PWM STEP
Bit 4
(PWM STEP SIZE =
4
4
4
206 msec
104 msec
Bit 3
69 msec
41 msec
26 msec
18 msec
10 msec
5 msec
3
3
3
1/255)
Bit 2
2
2
2
VALUE (HEX)
Bit 1
00h
40h
80h
FFh
1
1
1
.
.
.
.
.
.
.
.
.
SMSC EMC6D103
RAMP RATE
(LSb)
Bit 0
0
0
0
PWM
14.49
24.39
38.46
55.56
4.85
9.62
(HZ)
100
200
Datasheet
Default
Value
80h
80h
80h