W83793G Datasheet, PDF (67/131 Pages) Winbond – Winbond H/W Monitor

W83793G
FanDuty also has a special characteristic; it’s called sequential power-on. This function is used to
avoid system current over-load while system power-on and all fans start to spin. W83793G will turn on
each fan in sequence and it take 0.1sec to power on all fans.(12.5ms intervals for 8 Fans)
8.11.2.6 Fan PWM Output Frequency Prescalar (PWMPrescalar)
PWMPrescalar controls the output frequency in PWM mode. Here a large range of clock can be
selected to fit customer needs. Default output frequency is 25KHz.
Location :
PWM1Prescalar - Bank 0 Address BB_HEX
PWM2Prescalar - Bank 0 Address BC_HEX
PWM3Prescalar - Bank 0 Address BD_HEX
PWM4Prescalar - Bank 0 Address BE_HEX
PWM5Prescalar - Bank 0 Address BF_HEX
PWM6Prescalar - Bank 0 Address C0_HEX
PWM7Prescalar - Bank 0 Address C1_HEX
PWM8Prescalar - Bank 0 Address C2_HEX
Type : Read / Write(Only in Manual Mode)
Reset :
VSB5V(Pin 7) Rising,
Init Reset(CR40.Bit7) is set,
VDD5V(Pin 25) Rising @ RST_VDD_MD(CR40.Bit4) set,
SYSRSTIN_N(Pin 15) Falling @ SYSRST_MD(CR40.Bit5) set.
PWM1PRESCALAR ~ PWM8PRESCALAR
BIT
7
6
5
4
3
2
1
0
Name
CKSEL
Divisor
Reset
1
09_HEX
BIT
DESCRIPTION
CKSEL(clock source select).
7 0: 512Hz.
1: 250KHz.
6-0 Divisor(Clock Divisor). Clock frequency Divisor.
The clock source selected by CKSEL will be divided by Divisor and used as a Fan PWM output
frequency. There are 2 cases of Divisor depends on CKSEL.
If CKSEL equals 1, then output clock is simply equals to 250/(Divisor+1) KHz.
If CKSEL equals 0, output clock is 512Hz/MappedDivisor. MappedDivisor depends on Divisor[3:0] and
looks like below table.
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Publication Release Date: Dec. 11, 2006
Revision 1.0