Fan Control Device with High Frequency PWM Support and Hardware Monitoring Features
Datasheet
Table 8.9 PWM Duty vs Register Reading
CURRENT DUTY
VALUE (DECIMAL)
VALUE (HEX)
0%
0
00h
25%
50%
64
40h
80h
FFh
128
100%
255
During spin-up, the PWM duty cycle is reported as 0%.
Notes:
■
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. When a value is written to this register in manual mode there will be a delay before
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.
8.2.6
Register 3Eh: Company ID
Table 8.10 Register 3Eh: Company ID
Register
Address
Read/
Write
Bit 7
Bit 0
Default
Value
Register Name
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
(MSb)
(LSb)
3Eh
R
Company ID
7
6
5
4
3
2
1
0
5Ch
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.
8.2.7
Register 3Fh: Version / Stepping
Table 8.11 Register 3Fh: Version / Stepping
Register
Address
Read/
Write
Bit 7
Bit 0
Default
Value
Register Name
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
(MSb)
(LSb)
3Fh
R
Version / Stepping
VER3
VER
2
VER
1
VER
0
STP
3
STP
2
STP
1
STP0
6Ah
The four least significant bits of the Version / Stepping register [3:0] contain the current stepping of the
EMC6D103 silicon. Stepping numbers are to begin from a value of 08h, to indicate that the register
set is enhanced from previous hardware monitoring standards. The four most significant bits [7:4]
reflect the version number, which will be fixed at 0110b. For the A0 stepping of this device, the register
will read 01101000b. For the A1 stepping, this register will read 01101001b and so on.
Revision 0.4 (04-04-05)
SMSC EMC6D103
DATA5S8HEET
SMSC [ SMSC CORPORATION ]
