LPC47M112 SMSC Corporation, LPC47M112 Datasheet - Page 204

• Manufacturer Part Number: LPC47M112
• Description: ENHANCED SUPER I/O CONTROLLER WITH LPC INTERFACE
• Manufacturer: SMSC Corporation

Enhanced Super I/O Controller with LPC Interface
Datasheet
Note 1: t
Note 1: The blink rate is programmed through Bits[1:0] in LEDx register. When Bits[1:0]=00, LED is OFF.
SMSC DS – LPC47M112
NAME
NAME
programmed in the Fan Control register.
Bits[1:0]=01 indicates LED blink at 1Hz rate with a 50% duty cycle (0.5 sec ON, 0.5 sec OFF). Bits[1:0]=10
indicates LED blink at ½ Hz rate with a 25% duty cycle (0.5 sec ON, 1.5 sec OFF). When Bits[1:0]=11, LED
is ON.
TACH
t1
t2
t3
t1
t2
LEDx
is the clock used for the tachometer counter. It is 30.52 * DVSR, where the divisor (DVSR) is
FAN_TACHx
Pulse Time (1/2 Revolution Time=30/RPM)
Pulse High Time
Pulse Low Time
Period
Blink ON Time
DESCRIPTION
FIGURE 36 – FAN TACHOMETER INPUT TIMING
DESCRIPTION
FIGURE 37 – LED OUTPUT TIMING
t2
t1
Page 204
t1
t2
t3
4t
3t
MIN
t
MIN
TACH
TACH
TACH
1
0
1
1
TYP
TYP
MAX
0.5
2
1
MAX
UNITS
sec
sec
UNITS
µsec
µsec
µsec
Rev. 02/02/2005