HD64F2168 Datasheet, PDF (457/874 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer

14.8 IrDA Operation
IrDA operation can be used with SCI_1. Figure 14.36 shows an IrDA block diagram.
If the IrDA function is enabled using the IrE bit in SCICR, the TxD1 and RxD1 signals for SCI_1
are allowed to encode and decode the waveform based on the IrDA standard version 1.0 (function
as the IrTxD and IrRxD pins). Connecting these pins to the infrared data transceiver achieves
infrared data communication based on the system defined by the IrDA standard version 1.0.
In the system defined by the IrDA standard version 1.0, communication is started at a transfer rate
of 9600 bps, which can be modified as required. The IrDA interface provided by this LSI does not
incorporate the capability of automatic modification of the transfer rate; the transfer rate must be
modified through programming.
TxD1/IrTxD
RxD1/IrRxD
IrDA
Pulse encoder
Pulse decoder
TxD1
RxD1
SCI_1
SCICR
Figure 14.36 IrDA Block Diagram
Transmission: During transmission, the output signals from the SCI (UART frames) are
converted to IR frames using the IrDA interface (see figure 14.37).
For serial data of level 0, a high-level pulse having a width of 3/16 of the bit rate (1-bit interval) is
output (initial setting). The high-level pulse can be selected using the IrCKS2 to IrCKS0 bits in
SCICR.
The high-level pulse width is defined to be 1.41 µs at minimum and (3/16 + 2.5%) × bit rate or
(3/16 × bit rate) +1.08 µs at maximum. For example, when the frequency of system clock φ is 20
MHz, a high-level pulse width of at least 1.41 µs to 1.6 µs can be specified.
For serial data of level 1, no pulses are output.
Rev. 3.00, 03/04, page 417 of 830