Datasheet

Section 14 Serial Communication Interface (SCI, IrDA)
Rev.6.00 Mar. 18, 2009 Page 616 of 980
REJ09B0050-0600
14.8 IrDA Operation
When the IrDA function is enabled with bit IrE in IrCR, the SCI_0 TxD0 and RxD0 signals are
subjected to waveform encoding/decoding conforming to IrDA specification version 1.0 (IrTxD
and IrRxD pins). By connecting these pins to an infrared transceiver/receiver, it is possible to
implement infrared transmission/reception conforming to the IrDA specification version 1.0
system.
In the IrDA specification version 1.0 system, communication is started at a transfer rate of 9600
bps, and subsequently the transfer rate can be varied as necessary. As the IrDA interface in this
LSI does not include a function for varying the transfer rate automatically, the transfer rate setting
must be changed by software.
Figure 14.33 shows a block diagram of the IrDA function.
IrDA
Pulse encoder
Pulse decoder
TxD0/IrTxD
RxD0/IrRxD
SCI0
TxD
RxD
IrCR
Figure 14.33 Block Diagram of IrDA
Transmission: In transmission, the output signal (UART frame) from the SCI is converted to an
IR frame by the IrDA interface (see figure 14.34).
When the serial data is 0, a high pulse of 3/16 the bit rate (interval equivalent to the width of one
bit) is output (initial value). The high-level pulse can be varied according to the setting of bits
IrCKS2 to IrCKS0 in IrCR.