CHAPTER 13 SERIAL INTERFACE UART0
Preliminary User’s Manual U16315EJ1V0UD
261
(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) (refer to
Table 13-2
).
The contents of ASIS0 are reset to 0 when ASIS0 is read.
Table 13-2. Cause of Reception Error
Reception Error
Cause
Value of ASIS0
Parity error
The parity specified for transmission does not match the parity of the
receive data.
04H
Framing error
Stop bit is not detected.
02H
Overrun error
Reception of the next data is completed before data is read from
receive buffer register 0 (RXB0).
01H
(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 13-9, the internal processing of the reception operation
is delayed by two clocks from the external signal status.
Figure 13-9. Noise Filter Circuit
Internal signal B
Internal signal A
Match detector
In
Base clock
R
X
D0/SI10/P11
Q
In
LD_EN
Q