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6
D0–D7
The transcoder has eight status lines, D0 through D7. These lines can be
set as either inputs to record the state of switches or as outputs which will
reproduce switch states upon reception of a valid transmission.
CRT/LRN
When this line goes high, the transcoder will enter Learn Mode. If it is held
high for ten seconds, the transcoder will clear its memory. If it goes high
while the ENC_SEL line is high, the transcoder will enter Create Mode. If
it goes high while the SER_IO line is high, the transcoder will enter Serial
Mode.
ENC_SEL
If this line is tied high, it will operate as an encoder only. If it is tied low, the
transcoder will default to a decoder until it is set as a transcoder in Create
Mode.
SER_IO
This line is used for the Serial Interface Engine, which allows the transcoder
to be programmed by an external device. The transcoder will also use this
line to output the ID of the originating transcoder, status line states, and
custom data.
Confirm
This line will go high when the transcoder receives a confirmation that its
transmission was received correctly.
TR_PDN
This line can be used to automatically control power to an external
transceiver. When waiting for data the transcoder will toggle power to a
transceiver at a 10% on to 90% off ratio. The times are determined by the
selected baud rate.
TR_SEL
This line will toggle an external transceiver between transmit mode (high)
and receive mode (low).
TR_DATA
This line will send data to and receive data from an external transceiver.