EMC6D102_06 SMSC [SMSC Corporation], EMC6D102_06 Datasheet - Page 52

• Manufacturer Part Number: EMC6D102_06
• Description: Fan Control Device with Hardware Monitoring and Acoustic Noise Reduction Features
• Manufacturer: SMSC [SMSC Corporation]

Revision 0.4 (06-15-06)
7.2.7
7.2.8
Register
Address
Register
Address
3Eh
3Fh
CURRENT DUTY
Read/
Read/
Write
Write
The PWM duty cycle is represented as follows:
During spin-up, the PWM duty cycle is reported as 0%.
Notes:
Register 3Eh: Company ID
The Company ID register contains the company identification number. This number is a method for
uniquely identifying the part manufacturer.
This register is read only – a write to this register has no effect.
Register 3Fh: Version / Stepping
The four least significant bits of the Version / Stepping register [3:0] contain the current stepping of the
EMC6D102 silicon. The four most significant bits [7:4] reflect the version number.
The register is used by application software to identify which device has been implemented in the given
system. Based on this information, software can determine which registers to read from and write to.
R
R
100%
The PWMx Current Duty Cycle always reflects the current duty cycle on the associated PWM pin.
The PWMx Current Duty Cycle register is implemented as two separate registers: a read-only and
a write-only.
the programmed value can be read back by software. The hardware updates the read-only PWMx
Current Duty Cycle register on the beginning of a PWM cycle. If Ramp Rate Control is disabled,
the delay to read back the programmed value will be from 0 seconds to 1/(PWM frequency)
seconds. Typically, the delay will be 1/(2*PWM frequency) seconds.
25%
50%
0%
Version / Stepping
Register Name
Register Name
Company ID
When a value is written to this register in manual mode there will be a delay before
Table 7.4 PWM Duty vs Register Reading
Fan Control Device with Hardware Monitoring and Acoustic Noise Reduction Features
DATASHEET
VALUE (DECIMAL)
(MSb)
(MSb)
VER3
Bit 7
Bit 7
7
52
255
128
64
0
Bit 6
Bit 6
VER
6
2
Bit 5
Bit 5
VER
5
1
Bit 4
Bit 4
VER
4
0
Bit 3
Bit 3
STP
3
3
Bit 2
Bit 2
STP
2
2
VALUE (HEX)
Bit 1
Bit 1
STP
FFh
00h
40h
80h
1
1
SMSC EMC6D102
(LSb)
(LSb)
STP0
Bit 0
Bit 0
0
Datasheet
Default
Default
Value
Value
5Ch
65h