SCH3112I-NE SMSC [SMSC Corporation], SCH3112I-NE Datasheet - Page 382

• Manufacturer Part Number: SCH3112I-NE
• Description: LPC IO with 8042 KBC, Reset Generation, HWM and Multiple Serial Ports
• Manufacturer: SMSC [SMSC Corporation]

Rev 0.2 (09-28-04)
29.11
29.12
NAME
t1
t2
1. These Max values are due to internal Ring Oscillator. If 1Hz blink rate is selected for LED1 pin, the range will
vary from 0.33Hz to 1.0Hz. If 0.5Hz blink rate is selected for LED1 pin, the range will vary from 0.17Hz to 0.5Hz.
2. The blink rate is programmed through Bits[1:0] in LEDx register. When Bits[1:0]=00, LED is OFF. 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.
Notes:
1. This value is programmable by the PWM frequency bits located in the FRFx registers.
2. The PWM High Time is based on a percentage of the total PWM period (min=0/256*T
=255/256*T
nLEDx
Name
t1
t2
DESCRIPTION
Period
Blink ON Time
PWM
The following section shows the timing for the PWM[1:3] outputs.
nLEDx Timing
PWM Outputs
FANx
PWM Period (Note 1)
- low frequency option
- high frequency option
PWM High Time (Note 2)
). During Spin-up the PWM High Time can reach a 100% or Full On. (T
Description
Table 29.2 Timing for PWM[1:3] Outputs
Figure 29.29 PWMx Output Timing
t2
Figure 29.28 nLEDx Timing
DATASHEET
t1
t1
LPC IO with 8042 KBC, Reset Generation, HWM and Multiple Serial Ports
366
t2
10.7
11.4
Min
0
MIN
0
Typ
TYP
1 or 2
0.5
2
PWM
PWM
2
Max
90.9
42.7
99.6
= t1).
MAX
5.88
1.52
, max
1
1
SMSC SCH311X
UNITS
sec
sec
Datasheet
Units
msec
usec
%