EMC6D103-CK SMSC [SMSC Corporation], EMC6D103-CK Datasheet - Page 58

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

Revision 0.4 (04-04-05)
8.2.6
8.2.7
Register
Address
Register
Address
3Eh
3Fh
CURRENT DUTY
Read/
Read/
Write
Write
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
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.
R
R
100%
25%
50%
0%
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.
Version / Stepping
Register Name
Register Name
Company ID
Table 8.11 Register 3Fh: Version / Stepping
When a value is written to this register in manual mode there will be a delay before
Table 8.9 PWM Duty vs Register Reading
Table 8.10 Register 3Eh: Company ID
Fan Control Device with High Frequency PWM Support and Hardware Monitoring Features
VALUE (DECIMAL)
DATASHEET
(MSb)
(MSb)
VER3
Bit 7
Bit 7
7
128
255
64
58
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
00h
40h
80h
FFh
1
1
SMSC EMC6D103
(LSb)
(LSb)
STP0
Bit 0
Bit 0
0
Datasheet
Default
Default
Value
Value
5Ch
6Ah