Carrier Modulation - Epson S1C31W65 Technical Manual

13 UART (UART3)
S1C31 UART3
Figure 13.5.4.1 Example of Connections with an Infrared Communication Module
The transmit data output from the UART3 Ch.n transmit shift register is output from the USOUTn pin after the low
pulse width is converted into 3/16 by the RZI modulator in SIR method.
Modulator input (shift register output)
Modulator output (USOUTn)
The received IrDA signal is input to the RZI demodulator and the low pulse width is converted into the normal
width before input to the receive shift register.
Demodulator input (USINn)
Demodulator output (shift register input)
Notes: • Set the baud rate division ratio to 1/16 when using the IrDA interface function.
• The low pulse width (T

13.5.5 Carrier Modulation

The UART3 has a carrier modulation function.
Writing 1 to the UART3_nMOD.CAREN bit enables the carrier modulation function allowing carrier modulation
waveforms to be output according to the UART3_nMOD.PECAR bit setting. Data transmit control is identical to
that for normal interface even in this case.
Transmit data
CAREN = 0
CAREN = 1
USOUTn
PECAR = 0
(INVTX = 0)
CAREN = 1
PECAR = 1
CAREN = 0
CAREN = 1
USOUTn
PECAR = 0
(INVTX = 1)
CAREN = 1
PECAR = 1
(UART3_nMOD.CHLN = 1, UART3_nMOD.STPB = 0, UART3_nMOD.PREN = 1)
13-8
RXD
USINn
VCC
V
DD
GND
V
SS
TXD
USOUTn
LEDA
T
Figure 13.5.4.2 IrDA Transmission Signal Waveform
T
2
Figure 13.5.4.3 IrDA Receive Signal Waveform
) of the IrDA signal input must be CLK_UART3_n × 3 cycles or longer.
2
Start
1 0
bit
Figure 13.5.5.1 Carrier Modulation Waveform
Seiko Epson Corporation
VCC
AMP
GND
Infrared communication module
1
3
T
1
16
0 1 1
3
T
16
Parity
0 1 0
bit
S1C31W65 TECHNICAL MANUAL
1
Stop
bit
(Rev. 1.1)