
S1C8F626 TECHNICAL MANUAL
EPSON
65
5 PERIPHERAL CIRCUITS AND THEIR OPERATION (Serial Interface)
5.7.8 IR (Infrared-ray) interface
Modulator
SOUTx
(P11/P21)
IrDA I/F
LED
TCLK
TXD
LEDA
RXD
AGND
Vcc
GND
Photodiode
SINx
(P10/P20)
VDD
VSS
Serial I/F
Demodulator
S1C8F626
IR communication module (example)
AMP
Fig. 5.7.8.1 Configuration example of IR interface
The serial interface has a built-in modulator/
demodulator. Thus a circuit for infrared-ray
communication based on IrDA (Infrared Data
Association) standard can be configured by adding
a simple external circuit.
■ Setting of IR interface
The modulator/demodulator is only available
when the serial interface is set in asynchronous
mode.
When using the IR interface, change the function of
the serial interface using the IRSTx register. (See
Table 5.7.8.1.)
Table 5.7.8.1 Setting of IR interface
IRSTx
1
0
Setting
IR interface is used
IR interface is not used (normal interface is set)
At initial reset, the serial interface is set as general
interface.
When IR interface function is enabled, the serial
interface can invert the logic polarity of the input/
output signal according to the external infrared-ray
communication module. It is negative logic usually.
Invert the logic when inputting and outputting
positive logic signal.
The logic of the SINx input and SOUTx output can
be individually set by the IRILx register and the
IRTLx register. (See Tables 5.7.8.2 and 5.7.8.3.)
At initial reset, both the IRILx register and IRTLx
register are set to "0" (logic not inverted).
■ Control of IR interface
Figures 5.7.8.2 and 5.7.8.3 show the input/output
signal conversion by the modulator/demodulator.
The control procedure of data transfer is the same
as in case of the asynchronous mode. Refer to
Section 5.7.5, "Transmit-receive control".
TCLK
Modulator input (SIF output)
Modulator output (SOUTx)
12 3
8 9 10 11
16
3
×TCLK
Fig. 5.7.8.2 Input/output signal (during transmission)