18 UART
S1C17704 TECHNICAL MANUAL
EPSON
18-11
18.8 IrDA Interface
The UART module contains an RZI modulator/demodulator, allowing an infrared-ray communication circuit to be
configured based on IrDA 1.0 simply by adding an external circuit.
The transmit data output from the shift register of the UART is input to the modulator to convert the low pulse
width into 3/16 sclk cycles before it is output from the SOUT pin.
sclk
Modulator input (shift register output)
Modulator output (SOUT)
1
2 3
8 9 10 11
16
3
×
sclk
Modulator input (shift register output)
Modulator output (SOUT)
S1
D0
D1
D2
D3
D4
D5
D6
D7
P
S2
S3
(S1: Start bit, S2 & S3: Stop bits, P: Parity bit)
Figure 18.8.1 Transmit Signal Waveform
The received IrDA signal is input to the demodulator to convert the low pulse width into 16 sclk cycles before input
to the shift register for receiving. To detect low pulses input to the demodulator (minimum pulse width = 1.41 µs at
115200 bps), the demodulator uses a pulse detection clock selected from the prescaler output clocks separately with
the transfer clock sclk.
(S1: Start bit, S2 & S3: Stop bits, P: Parity bit)
sclk
irclk
Demodulator input (SIN)
Demodulator output (shift register input)
1
2 3 4
16
16
×
sclk
2
×
irclk or more
Demodulator input (SIN)
Demodulator output (shift register input)
S1
D0
D1
D2
D3
D4
D5
D6
D7
P
S2
S3
Figure 18.8.2 Receive Signal Waveform
Enabling the IrDA mode
To use the IrDA interface function, set the IRMD bit (D0/UART_EXP register) to 1. This enables the RZI
modulator/demodulator.
∗
IRMD
: IrDA Mode Select Bit in the UART Expansion (UART_EXP) Register (D0/0x4105)
Note
: This setting must be performed before setting other UART conditions.
Summary of Contents for S1C17704
Page 1: ...TECHNICAL MANUAL S1C17704 CMOS 16 BIT SINGLE CHIP MICROCOMPUTER ...
Page 22: ...1 OVERVIEW 1 10 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 42: ...3 MEMORY MAP BUS CONTROL 3 12 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 82: ...6 INTERRUPT CONTROLLER ITC 6 26 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 108: ...8 CLOCK GENERATOR CLG 8 8 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 112: ...9 PRESCALER PSC 9 4 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 138: ...10 I O PORTS P 10 26 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 156: ...11 16 BIT TIMERS T16 11 18 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 208: ...14 8 BIT OSC1 TIMER T8OSC1 14 16 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 234: ...16 STOPWATCH TIMER SWT 16 14 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 242: ...17 WATCHDOG TIMER WDT 17 8 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 264: ...18 UART 18 22 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 300: ...20 I2C 20 20 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 320: ...21 REMOTE CONTROLLER REMC 21 20 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 360: ...24 ON CHIP DEBUGGER DBG 24 6 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 362: ...25 BASIC EXTERNAL WIRING DIAGRAM 25 2 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...