LICAL-TRC-MT Linx Technologies Inc, LICAL-TRC-MT Datasheet - Page 6

• Manufacturer Part Number: LICAL-TRC-MT
• Description: IC TRANSCODER MT BI-DIR 20-SSOP
• Manufacturer: Linx Technologies Inc
• Series: MTr
• Type: Transcoderr

Specifications of LICAL-TRC-MT

• Package / Case: 20-SSOP
• Applications: RF, IR
• Mounting Type: Surface Mount
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 2 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: LICAL-TRC-MTTR

OPERATION WITH THE MS SERIES
SERIAL OUTPUT
Figure 5: MT Series Transcoder Serial Output
TX ID
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The MT Series transcoders are fully compatible with the MS Series encoders
and decoders. Tying the ENC_SEL line high makes the transcoder operate just
like an MS Series encoder. Tying this line low enables it to become an MS
decoder or a transcoder, depending on how it is set-up.
There are two important issues of note when using the transcoders with the MS
Series. First, only two of the MS baud rates are supported by the MT, 9,600bps
and 28,800bps. Second, the MS Series will not respond to the advanced
features of the MT, like the custom data and Targeted Device Addressing.
The main advantage offered by the MT over the MS is the serial interface. This
allows a number of advanced options to be realized. Some other advantages are
more users (60 vs. 40), lower duty cycle (25% vs. 50%), and the serial output on
every packet.
Upon reception of every valid packet, the transcoder outputs a serial data stream
consisting of a start byte, TX ID byte, status line state byte, custom data byte,
and a stop byte. The start byte is 0x00 and the stop byte is 0xFF.
The status line byte reflects the states of the status lines, ‘1’ for on and ‘0’ for off.
This represents the current logic states of the outputs, not the command that was
received, so that the states of latched lines are correctly represented. Line D0
corresponds to bit b0 in the byte, D1 corresponds to b1, and so forth. This allows
applications that use an embedded microcontroller to read the transmitted
commands without having to monitor eight hardware lines. The TXID and
Custom Data bytes are described below.
The bytes are output asynchronously least significant bit first with one start bit,
one stop bit, and no parity at the baud rate determined by the SEL_BAUD line.
These are described more in the Serial Interface section and Application Note
AN-00157 shows some example software to read the TX_ID and associate it
with a particular transcoder.
The transcoder outputs an eight-bit binary number on the SER_IO line to identify
which learned transcoder sent the transmission. The number normally
corresponds to the order in which the transcoder was learned, so the first
transcoder learned will get number ‘1’, the second will get number ‘2’, and so on.
An exception arises when the memory is full, in which case the first numbers are
overwritten as described in the Learn Mode section. An exception also arises if
the serial interface is used to write an address to a specific location in memory.
start
SER_IO
b0
b1
b2
b3
b4
00
b5
TX ID
b6
STATUS CUSTOM
b7
stop start
b0
b1
FF
b2
b3
b4
b5
b6
b7
stop
CUSTOM DATA TRANSMISSION
SERIAL MODE
Figure 6: MT Series Transcoder Serial Programming
SER_IO (INPUT/OUTPUT)
MODE_IND (OUTPUT)
The MT Series offers the option of sending one byte of custom data with the
command packet. The custom byte is entered into the transcoder through the
SIE using the Read and Write Custom Data Value commands. This option is
enabled or disabled using the Enable and Disable Custom Data commands. The
custom data byte is output on the receiving end with the TX_ID and Status bytes.
Custom Data Transmission only needs to be enabled on the transmitting side.
The receiving side identifies the packet as containing custom data and outputs
the byte. This option is disabled by default and the receiving transcoder outputs
a value of 0xFF for the custom byte.
One of the most powerful features of the MT Series is its Serial Interface Engine
(SIE). The SIE allows the user to monitor and control the device configuration
settings through an automated system or PC rather than manually through the
hardware lines. While serial programming is not required for basic operation, it
enables the advanced features offered by the MT, such as Targeted Device
Addressing and Custom Data transmissions.
The SIE consists of twenty commands. The transcoder outputs an
acknowledgement once it has received each command, and then a response of
up to four additional bytes if required by the command.
Serial Mode is entered by taking the CRT/LRN line and the SER_IO line high at
the same time. The MODE_IND line goes high for as long as the SER_IO line is
an output, allowing it to be used with RS-232 style handshaking. Each byte is
sent LSB first with one start bit, one stop bit, and no parity at the baud rate
determined by the SEL_BAUD line. After the last command byte is received,
there will be a 5mS pause while the transcoder processes the command, then it
outputs the acknowledgement and a response if appropriate. The figure below
shows the order and timing of the serial interface.
The timings associated with each command and the transcoder’s response are
listed in Tables 4 (9,600bps) and 5 (28,800bps).
It should be noted that all of the settings are written into non-volatile memory, so
they will be retained if power is removed from the chip. This includes all values,
such as custom byte and target address, as well as the enabled / disabled states.
CRT_LRN (INPUT)
start
b0
b1
b2
b3
00
b4
C
b5
C
SER_IO = INPUT
Command
b6
C
b7
C
stop start
C
C
FF
b0
1ms
b1
b2
4ms
b3
00
b4
b5
A
Acknowledge/Response
b6
A
SER_IO = OUTPUT
b7
A
stop
R
R
R
R
FF
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