Toshiba TMP92CM22FG Computer Hardware User Manual


 
TMP92CM22
2007-02-16
92CM22-169
3.9.5 Support for IrDA Mode
SIO0 includes support for the IrDA 1.0 infrared data communication specification.
Figure 3.9.24 shows the block diagram.
Figure 3.9.24 Block Diagram of IrDA
(1) Modulation of transmission data
When the transmission data is 0, output “H” level with either 3/16 or 1/16 times for
width of baud-rate (Selectable in software). When data is “1”, modem output “L” level.
Figure 3.9.25 Example of Modulation of Transmission Data
(2) Modulation of receiving data
When the receive data has the effective high level pulse width (Software selectable),
the modem outputs “0” to SIO0. Otherwise modem outputs “1” to SIO0. Receive pulse
logic is selectable by SIRCR<RXSEL>.
Figure 3.9.26 Example of Modulation of Receiving Data
Transmission
data
SIO0
IR modulator
IR
demodulator
Receive
data
IR transmitter & LED
IR receiver
Modem IR module
TXD0
RXD0
IR output
IR input
TMP92CM22
Start
Transmission
data
Stop
0 00010 11
Output after
modulation
Start
Data after
modulation
Stop
11001 01
0
Receiving pulse
<RXSEL> = “0”
Receiving pulse
<RXSEL> = “1”