SC9243
FUNCTIONAL DESCRIPTION
1. TRANSMISSION CODE
The transmission code consists of a leader code, 16 bits system code, and 8 bits data code. The inverse of the
data code is also sent simultaeously. The following diagram shows this one frame construction.
It should be noted that System Code Bit 7(S7) has a fixed value of “1”.
The leader code consists of a 4.5 ms carrier waveform followed by a 4.5 ms OFF waveform. It is used as the
leader for the following codes. Thus, when reception is configured by a microcomputer, the time relationship
between the detection of the reception and the other processes can be managed efficiently. The code uses the
PPM (Pulse Position Modulation )Method, with “0”and “1”differentiated by the time between pulses.
2. REMOTE OUTPUT WAVEFORMS
SC9243 Remote Output Waveforms are given in the diagram below.(for fosc=455KHz)
DOUT Output Waveform
Key On
about 38ms
Data Transimission Waveform abort 108ms
Continuous Transmission Waveform
about 108ms
Data Transmission Waveform
Leader Pulse
System Code
System Code
Key Data Code
Key Data Code
9ms 17.92ms~36ms
01 1 01
4.5ms
4.5ms
9ms 1.2ms 2.25ms
0.56ms
Continuous Transmission Waveform
0.56ms
27ms
4.5ms
4.5ms
9ms
Carrier Waveform
0.56ms
2.25ms
in case of S0(System Code Bit 0)=0
2/3
1/3
38KHz
When oscillation frequency is 455 KHz, a signal is outputted after pulse is modulated by 38 KHz of duty 1/3
(which is 1/12 of the carrier generation circuit).
Note: In preparing the firmware of the receiving circuit, please strictly follow the following instructions:
1. System Codes: The same code is transmitted twice and therefore, always decode these 2 codes and check
if they are in agreement with each other.
2. Key Data Codes: The Key Data Code and its inversed code are always transmitted together, therefore,
check if they are in agreement with each other.
HANGZHOU SILAN MICROELECTRONICS CO.,LTD
Http: www.silan.com.cn
REV:1.1 2005.12.15
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