Remote Control Input - Sanyo AVM-2550S Training Manual

The data received from the remote control is first amplified to 5 V digital
pulses by the pre-amplifier module A1901 and then input to the CPU on pin
10. See Remote Transfer Code figure below. The remote data is a transfer
code consisting of a leader code, an 8-bit custom code, and an 8-bit data
code. A signal transfer code is 32 bits which allows the custom and data
codes to be sent twice, once in the normal mode and then inverted. This
provides a type of redundancy check to prevent misoperation.
IC801
CPU

REMOTE CONTROL INPUT

L1901
R1909
10
D1901 C1902
(7.5V)
Remote Input Circuit
Custom and Data codes differentiate between the "1" and "9" values by the
pulse duration. See "1" and "0" Pulse Duration diagram below.
The custom code is a unique code assigned to each manufacturer.
Its purpose is to help prevent operation of the TV by remote controls for other
components such as VCRs, CD players etc. The code assigned to our
company is 38H. See Custom Code figure below. The data code is the
command, or channel number.
ALWAYS
5V
1
A1901
2
RC PRE-AMP
3
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