Datasheet

Section 15 Serial Communication Interface (SCI, IrDA)
Rev. 4.00 Sep 27, 2006 page 483 of 1130
REJ09B0327-0400
15.3.5 IrDA Operation
Figure 15.21 shows a block diagram of the IrDA function.
When the IrDA function is enabled with bit IrE in KBCOMP, the SCI channel 2 TxD2 and RxD2
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 the this
LSI does not include a function for varying the transfer rate automatically, the transfer rate setting
must be changed by software.
IrDA
Pulse encoder
Pulse decoder
KBCOMP
TxD2/IrTxD
RxD2/IrRxD
SCI2
TxD
RxD
Figure 15.21 Block Diagram of IrDA Function
Transmission
In transmission, the output signal (UART frame) from the SCI is converted to an IR frame by the
IrDA interface (see figure 15.22).
When the serial data is 0, a high-level pulses 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 KBCOMP.