Toshiba TLCS-900/H1 Series Data Book page 176

3.9.5 Support for IrDA
SIO0 includes support for the IrDA 1.0 infrared data communication specification.
Figure 3.9.30 shows the block diagram.
Transmisison data
SIO0
Receive data
TMP92C820F
(1) Modulation of the transmission data
When the transmit data is 0, the modem outputs 1 to TXD0 pin with either 3/16 or
1/16 times for width of baud-rate. The pulse width is selected by the SIRCR<PLSEL>.
When the transmit data is 1, the modem outputs 0.
Transmission data
Start
TXD0 pin
(2) Modulation of the receive data
When the receive data is the effective width of pulse "1", the modem outputs "0" to
SIO0. Otherwise the modem outputs "1" to SIO0. The effective pulse width is selected
by SIRCR<SIRWD3 to SIRWD0>.
RXD0 pin
Receive data
Start
TXD0
IR modulator
Modem
RXD0
IR demodulator
Figure 3.9.30 Block Diagram
0 1 0 0
Figure 3.9.31 Transmission example
1 0 0
Figure 3.9.32 Receiving example
92CH21 - 172
IR transmitter & LED
IR receiver
1 1 0
1 0 1 1
TMP92CH21
IR output
IR input
0 Stop
0 Stop