R01UH0823EJ0100 Rev.1.00
Page 1110 of 1823
Jul 31, 2019
RX23W Group
34. IrDA Interface
34.3
Operation
34.3.1
Transmission
In transmission, the signals output from the SCI5 (UART frames) are converted to the IR frame data through the IrDA
interface (see
). When the IRCR.IRTXINV bit is 0 and data is 0, high-level pulses with 3/16 of the bit period
are output (initial setting). The high-level pulse width can be changed by setting the IRCR.IRCKS[2:0] bits. The standard
prescribes that the minimum high-level pulse width should be 1.41 μs and the maximum high-level pulse width should
be the bit period × (3/16 + 2.5%) or (the bit period × 3/16) + 1.08 μs. When the peripheral module clock PCLK is 20
MHz, the minimum high-level pulse width can be set to 1.6 μs (101b: PCLK/32) as shown in
. When data is
1, no pulses are output.
Figure 34.2
IrDA Transmission/Reception
UART frame
Data
0
1
0
1
0
0
1
1
0
1
Start bit
Stop bit
1
1
1
1
1
0
0
0
0
0
IR frame
Data
Start bit
Stop bit
Bit period
The pulse width is 1.4 µs to
the bit period x (3/16 + 2.5%)
or (the bit period × 3/16) + 1.08 µs
Transmission
Reception