EMC6D103-CK SMSC [SMSC Corporation], EMC6D103-CK Datasheet - Page 56

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

Revision 0.4 (04-04-05)
8.2.4
Register
Address
2Ch
2Dh
2Ah
2Bh
2Eh
2Fh
28h
29h
(SENSOR ERROR)
TEMPERATURE
Read/
Write
■
■
■
Registers 28-2Fh: Fan Tachometer Reading
The Fan Tachometer Reading registers contain the number of 11.111µs periods (90KHz) between full
fan revolutions. Fans produce two tachometer pulses per full revolution. These registers are updated
at least once every second.
This value is represented for each fan in a 16 bit, unsigned number.
The Fan Tachometer Reading registers always return an accurate fan tachometer measurement, even
when a fan is disabled or non-functional, including when the start bit=0.
When one byte of a 16-bit register is read, the other byte latches the current value until it is read, in
order to ensure a valid reading. The order is LSB first, MSB second.
R
R
R
R
R
R
R
R
-127°c
127°c
-50°c
50°c
0°c
Zone 1 is controlled by Remote Diode 1 Temp Reading
Zone 2 is controlled by Internal Temp Reading (Ambient Temperature Sensor)
Zone 3 is controlled by Remote Diode 2 Temp Reading
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Table 8.7 Registers 28-2Fh: Fan Tachometer Reading
Register Name
Tach1 MSB
Tach2 MSB
Tach3 MSB
Tach4 MSB
Tach1 LSB
Tach2 LSB
Tach3 LSB
Tach4 LSB
Table 8.6 Temperature vs. Register Reading
Fan Control Device with High Frequency PWM Support and Hardware Monitoring Features
READING (DEC)
DATASHEET
(MSb)
Bit 7
15
15
15
15
7
7
7
7
-127
127
-50
50
0
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56
Bit 6
14
14
14
14
6
6
6
6
Bit 5
13
13
13
13
5
5
5
5
Bit 4
12
12
12
12
4
4
4
4
Bit 3
11
11
11
11
3
3
3
3
Bit 2
READING (HEX)
10
10
10
10
2
2
2
2
Bit 1
CEh
7Fh
81h
00h
32h
80h
1
9
1
9
1
9
1
9
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SMSC EMC6D103
(LSb)
Bit 0
0
8
0
8
0
8
0
8
Datasheet
Default
Value
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A