F71872
(1). When expected count is FFFFh, PWMOUT duty-cycle (PWM_DUTY)will be set to 00h to turn off fan.
(2). When expected count is 0000h, PWMOUT duty-cycle (PWM_DUTY) will be set to FFh to turn on fan
with full speed.
(3). If both (1) and (2) are not true and KEEP_STOP (see INDEX 60h) is set to 0:
(a). When PWMOUT duty-cycle decrease to STOP_DUTY(≠ 00h), obviously the duty-cycle will
decrease to 00h next, F71872 will keep duty-cycle at 00h 3 seconds1. After that, F71872 starts to
compare current fan count and expected count in order to increase or decrease its duty-cycle.
This ensures that if there is any glitch during the 3 seconds1 period, F71872 will ignore it.
(b). When PWMOUT duty-cycle increase from 00h to START_DUTY(≠ 00h), F71872 also will keep
duty-cycle at START_DUTY 3 seconds1. After that, F71872 starts to compare current fan count
and expected count in order to increase or decrease its duty-cycle. This ensures that if there is
any glitch during the 3 seconds1 period, F71872 will ignore it.
Note 1: The period of HOLD_DUTY_TIME can be programmed at INDEX 67h of FAN1.
START
STOP
START
STOP
6.4.6 FAN_FAULT#
Fan_Fault will be asserted ( throuth PME# Pin 73) when the fan speed doesn’t meet the expected fan
speed within a programmable period (default is 3 seconds) when PWMOUT duty-cycle is 100%.
22
July, 2007
V0.28P
FINTEK [ FEATURE INTEGRATION TECHNOLOGY INC. ]
