Toshiba TLCS-900/L1 Series Manual page 152

3.9.5 Support for IrDA
SIO0 includes support for the IrDA 1.0 infrared data communication specification.
Figure 3.9.24 shows the block diagram.
Transmisison data
SIO0
Receive data
(1) Modulation of the transmission data
When the transfer 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 transfer data is 1, the modem outputs 0.
Transmission data
Start
TXD0 pin
Figure 3.9.25 Modulation Example of Transfer Data
(2) Modulation of the receive data
When the receive data has the effective high level pulse width (Software selectable),
the modem outputs 0 to SIO0. Otherwise the modem outputs 1 to SIO0. The receive
pulse logic is also selectable by SIRCR<RXSEL>.
Receiving pulse
<RXSEL = "0">
Receiving pulse
<RXSEL = "1">
Start
Data after
modulation
Figure 3.9.26 Demodulation Example of Receive Data
IR modulator
Modem
IR demodulator
TMP91C824
Figure 3.9.24 IrDA Block Diagram
0 1 0
1 0 0
91C824-150
TXD0
IR transmitter & LED
RXD0
IR receiver
0 1 1 0
1 0 1 1
TMP91C824
IR output
IR input
0 Stop
0
Stop
2008-02-20