EMC2302 datasheet(37/70 Pages) MICROCHIP

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 2021 Microchip Technology Inc.

DS20006532A-page 37

EMC2301/2/3/5

6.12

Fan Drive Setting Register

The Fan Drive Setting register always displays the cur-

rent setting of the respective fan driver. Reading from

any of the registers will report the current fan speed

setting of the appropriate fan driver regardless of the

operating mode. Therefore it is possible that reading

from this register will not report data that was

previously written into this register.

While the RPM-based Fan Speed Control algorithm is

active, this register is read-only. Writing to the register

will have no effect and the data will not be stored. The

contents of the register represent the weighting of each

bit in determining the final output voltage.

bit 1-0

PMB1[1:0]: Sets the PWM1 base frequency

11 = PWM 1 base is 2.441 kHz.

10 = PWM 1 base is 4.882 kHz.

01 = PWM 1 base is 19.53 kHz.

00 = PWM 1 base is 26.00 kHz.

PWM BASEF123 - PWM 1, 2 AND 3 BASE FREQUENCY CONFIGURATION

FAN DRIVE SETTING - FAN DRIVE SETTING REGISTER

(ADDRESSES 30H, 40H, 50H, 60H, 70H)

RW-0

FxSP[7:0]

bit 7

bit 0

Legend:

R = Readable bit

W = Writable bit

U = Unimplemented bit, read as ‘0’

-n = Value at POR

‘1’ = Bit is set

‘0’ = Bit is cleared

x = Bit is unknown

bit 7-0

FxSP]7:0]: Fan Speed Setting, where “x” represents PWM1 through 5 based on device features. PWM

duty cycle is calculated in Equation 4-1.

EMC2302 Datasheet(PDF) 37 Page - Microchip Technology