Receive Errors; Framing Error - Epson S1C17F13 Technical Manual

S1C17 UART
Figure 10.
The transmit data output from the UART 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 and inverted. The USOUTn pin output sig-
nal can be inverted by setting the UAnMOD.INVIRTX bit to 1.
Modulator input (shift register output)
Modulator output (USOUTn)
UAnMOD.INVIRTX bit = 0
UAnMOD.INVIRTX bit = 1
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. The USINn pin input signal can be inverted prior to being demodu-
lated by setting the UAnMOD.INVIRRX bit to 1.
Demodulator input (USINn)
UAnMOD.INVIRRX bit = 0
UAnMOD.INVIRRX bit = 1
Demodulator output (shift register input)
Note: The low pulse width (T
10.6

Receive Errors

Three different receive errors, framing error, parity error, and overrun error, may be detected while receiving data.
Since receive errors are interrupt causes, they can be processed by generating interrupts.
10.6.1

Framing Error

The UART determines loss of sync if a stop bit is not detected (when the stop bit is received as 0) and assumes that
a framing error has occurred. The received data that encountered an error is still transferred to the receive data buf-
fer and the UAnINTF.FEIF bit (framing error interrupt flag) is set to 1 when the data becomes ready to read from
the UAnRXD register.
Note: Framing error/parity error interrupt flag set timings
These interrupt flags will be set after the data that encountered an error is transferred to the re-
ceive data buffer. Note, however, that the set timing depends on the buffer status at that point.
• When the receive data buffer is empty
The interrupt flag will be set when the data that encountered an error is transferred to the re-
ceive data buffer.
S1C17F13 TeChniCal Manual
(Rev. 1.0)
RXD
USINn
VCC
V
DD
GND
V
SS
TXD
USOUTn
LEDA
5.4.1 Example of Connections with an Infrared Communication Module
Figure 10. 5.4.2 IrDA Transmission Signal Waveform
T
2
Figure 10. 5.4.3 IrDA Receive Signal Waveform
) of the IrDA signal input must be CLK_UART × 3 cycles or longer.
2
Seiko epson Corporation
VCC
AMP
GND
Infrared communication module
T
1
3
T
1
16
10 UART (UART)
3
T
1
16
10-7