CHAPTER 14 SERIAL INTERFACE UART0
Preliminary User’s Manual U17260EJ3V1UD
341
(e) Reception
error
Three types of errors may occur during reception: a parity error, framing error, or overrun error. If the error
flag of asynchronous serial interface reception error status register 0 (ASIS0) is set as a result of data
reception, a reception error interrupt (INTSR0) is generated.
Which error has occurred during reception can be identified by reading the contents of ASIS0 in the reception
error interrupt (INTSR0) servicing (see
Figure 14-3
).
The contents of ASIS0 are cleared to 0 when ASIS0 is read.
Table 14-3. Cause of Reception Error
Reception Error
Cause
Parity error
The parity specified for transmission does not match the parity of the receive data.
Framing error
Stop bit is not detected.
Overrun error
Reception of the next data is completed before data is read from receive buffer
register 0 (RXB0).
(f) Noise filter of receive data
The R
X
D0 signal is sampled using the base clock output by the prescaler block.
If two sampled values are the same, the output of the match detector changes, and the data is sampled as
input data.
Because the circuit is configured as shown in Figure 14-10, the internal processing of the reception operation
is delayed by two clocks from the external signal status.
Figure 14-10. Noise Filter Circuit
Internal signal B
Internal signal A
Match detector
In
Base clock
R
X
D0/SI10/P11
Q
In
LD_EN
Q