Linx Technologies LICAL-TRC-MT - Manual (Page 5)

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Pin Assignments
VCC
D6
D7
CRT/LRN
ENC_SEL
SER_IO
CONFIRM
TR_PDN
TR_SEL
TR_DATA GND
D5
D4
D3
LATCH
SEL_BAUD
MODE_IND
D2
D1
D0
1
2
3
4
5
6
7
8
9
10 11
12
13
14
15
16
17
18
19
20 LICAL-TRC-MT
Pin Descriptions
Figure 5: MT Series Transcoder Pin Assignments (Top View)
Pin Descriptions
Pin Number Name I/O Description
1 V
CC
Supply Voltage
2, 3, 11–13,
17–19
D0–D7 I/O
Status Lines. Each line can be configured
as either an input to register button or
contact closures or as an output to control
application circuitry.
4 CRT/LRN I
Create / Learn Mode Activation Line.
When this line goes high, the transcoder
enters Learn Mode. If it is held high for ten
seconds, the transcoder clears its memory.
If it goes high while the ENC_SEL line is
high, the transcoder enters Create Mode.
If it goes high while the SER_IO line is high,
the transcoder enters Serial Mode.
5 ECN_SEL I
Encoder Only Select Line. If this line is tied
high, the MT operates as an encoder only.
If it is tied low, the MT defaults to a decoder
until it is set as a transcoder in Create Mode.
6 SER_IO I/O
Serial Interface Line. This line is used for
the Serial Interface Engine, which allows
the transcoder to be programmed by an
external device. The transcoder also uses
this line to output the ID of the originating
transcoder, status line states, and custom
data.
7 CONFIRM O
Transmission Confirmation Line. This line
goes high when the transcoder receives
a confirmation that its transmission was
received correctly.
Pin Descriptions
Pin Number Name I/O Description
8 TR_PDN O
Transceiver Power Control Line. This line
can be used to automatically control power
to an external transceiver. When waiting
for data, the transcoder toggles power to
a transceiver at a 10% on to 90% off ratio.
The times are determined by the selected
baud rate.
9 TR_SEL O
Transceiver Mode Control Line. This line
toggles an external transceiver between
transmit mode (high) and receive mode
(low).
10 TR_DATA I/O
Transceiver Data Line. This line sends
data to and receives data from an external
transceiver.
14 MODE_IND O
Mode Indicator Output. This line switches
when a valid transmission is received, when
Learn Mode or Create Mode is entered, and
when the memory is cleared. This allows for
the connection of an LED to indicate to the
user that these events have taken place.
15 SEL_BAUD I
Baud Rate Selection Line. This line is used
to select the baud rate of the serial data
stream. If the line is high, the baud rate
is 28,800bps, if it is low, the baud rate is
9,600bps. The baud rate must be set before
power up. The transcoder will not recognize
any change in the baud rate setting after it
is on.
16 LATCH I
Set Latched Outputs. If this line is low, then
the data outputs are momentary (active for
as long as a valid signal is received). If this
line is high, the outputs are latched (when
a signal is received to make a particular
data line high, it remains high until another
transmission is received instructing it to go
low) by default, but individual status lines
can be set as latched or momentary through
the SIE.
20 GND Ground
None of the input lines have internal pull-up or pull-down resistors. The input lines must
always be in a known state (either GND or V
CC
) at all times or the operation may not be
predictable. The designer must ensure that the input lines are never floating, either by us-
ing external resistors, by tying the lines directly to GND or V
CC
, or by use of other circuits
to control the line state.
Figure 6: MT Series Transcoder Pin Descriptions