EM78468AQ EMC [ELAN Microelectronics Corp], EM78468AQ Datasheet - Page 52

• Manufacturer Part Number: EM78468AQ
• Description: 8-BIT Microcontroller
• Manufacturer: EMC [ELAN Microelectronics Corp]

EM78468
8-BIT Microcontroller
48 •
4.10 Infrared Remote Control Application / PWM Waveform Generate
This LSI can output infrared carrier in a friendly manner or in PWM standard waveform.
The IR and PWM waveform generated functions include an 8-bits down-count timer,
high-pulse width timer, low-pulse width timer, and IR control register. The IR system
block diagram is show in Fig.21, The IROUT pin waveform is determined by IR control
register (RE), IOC90 (Counter 1, 2 control register), IOCA0 (high-pulse width timer,
low-pulse width timer control register), IOCC0 (Counter 2 preset), IOCD0 (high-pulse
width timer preset register), and IOCE0 (low-pulse width timer preset register). Details on
Fcarrier, high-pulse time, and low pulse time are explained as follows :
If Counter 2 source clock is F
If high-pulse width timer source clock is FT (this clock source can set by IOCA1);
If low-pulse width timer source clock is FT (this clock source can set by IOCA1);
F
T
T
carrier
high
low
pulse
pulse
=
2
time
time
*
1 (
=
=
+
prescaler
decimal
prescaler
of
*
*
1 (
1 (
+
T
counter
+
(this clock source can set by IOC91);
decimal
decimal
(This specification is subject to change without further notice)
2
F
preset
of
T
of
low
high
value
Product Specification (V1.1) 04.11.2005
F
F
T
pulse
T
pulse
(
IOCC
width
0
width
))
*
prescaler
timer
timer
value
value
(
IOCE
(
IOCD
0
))
0
))