NEC V854 UPD703006 User Manual page 219

Figure 8-4. Asynchronous Serial Interface Reception Completion Interrupt Timing
RXD (input)
INTSR interrupt
(d) Reception error flag
Three error flags, parity error, framing error, and overrun error flags, are related with the reception
operation.
The receive error interrupt request occurs as a result of ORing these three error flags.
By reading the contents of the ASIS registers, the error which caused the receive error interrupt (INTSER)
can be identified.
The contents of the ASIS registers are reset to 0 when the receive buffer (RXB or RXBL) is read or the
next data frame is received (if the next data contains an error, the corresponding error flag is set).
Receive
Parity error Parity specified during transmission does not coincide with parity of receive data
Framing error Stop bit is not detected
Overrun error Next data is completely received before data is read from receive buffer
RXD (input)
INTSR interrupt
INTSER interrupt
CHAPTER 8 SERIAL INTERFACE FUNCTION
D0 D1 D2
Start
Figure 8-5. Receive Error Timing
D0 D1 D2
Start
User's Manual U11969EJ3V0UM00
Parity/
D6 D7
extend
Error Cause
Parity/
D6 D7
extend
Stop
Stop
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