em78p257 ELAN Microelectronics Corp, em78p257 Datasheet - Page 59

• Manufacturer Part Number: em78p257
• Description: 8-bit Microcontroller
• Manufacturer: ELAN Microelectronics Corp

4.12 INFRARED REMOTE APPLICATION MODE
This specification is subject to change without prior notice.
1. Overview & Features
IR OUT
Low-time
Overview:
Features:
EM78P257A/B is designed for use in universal infrared remote commander applications. Fig.26 shows the
hardware modulator of EM78P257A/B. It can generate programmable pulse trains for driving an infrared LED.
• Power saving : Idle and Stop modes are provided
• Hardware Modulator providing pulse bursts , with :
-- programmable duty factor for each pulse
-- programmable number of pulse
• Watchdog timer to keep the transmitter from being locked or malfunction
• On-chip oscillator: 455kHz to 24MHz
Low-time = 2 (Low-time register = 2
start
pulse #1
High-time
pulse #2
Fig. 26 Example Pulse Train Output of IR OUT Pin
) High-time = 4(High-time register = 4) number of pulse = 3
pulse #3
interrupt
end
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Elapse time by software
EM78P257
07.27.2004 (V1.4)
OTP ROM