CHAPTER 11 SERIAL INTERFACE UART0 (
µ
PD78F0102H AND 78F0103H ONLY)
Preliminary User’s Manual U16846EJ1V0UD
217
(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 request (INTSR0) is generated.
Which error has occurred during reception can be identified by reading the contents of ASIS0 in the reception
error interrupt servicing (INTSR0) (see Figure 11-3).
The contents of ASIS0 are reset to 0 when ASIS0 is read.
Table 11-3. 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 11-10, the internal processing of the reception operation
is delayed by two clocks from the external signal status.
Figure 11-10. Noise Filter Circuit
Internal signal B
Internal signal A
Match detector
In
Base clock
R
X
D0/SI10/P11
Q
In
LD_EN
Q