uPD789074 Subseries 8-Bit Single-Chip Microcontrollers UD - Home

CHAPTER 9 SERIAL INTERFACE 20(c) Asynchronous serial interface status register 20 (ASIS20)ASIS20 is read with a 1-bit or 8-bit memory manipulation instruction.RESET input clears ASIS20 to 00H.Symbol 7 6 5 4 3 2 1 0 Address After reset R/WASIS200 0 0 0 0 PE20 FE20 OVE20FF71H 00H RPE20Parity error flag01Parity error did not occurParity error occurred (when the parity of transmit data did not match)FE2001Framing error did not occurFlaming error flagFraming error occurred (when stop bit was not detected) Note 1OVE2001Overrun error did not occurOverrun error flagOverrun error occurred Note 2(when the next receive operation was completed before the data was read from the receive buffer register)Notes 1. Even when the stop bit length is set to 2 bits by setting bit 2 (SL20) of asynchronous serialinterface mode register 20 (ASIM20), the stop bit detection at reception is performed with 1bit.2. Be sure to read receive buffer register 20 (RXB20) when an overrun error occurs. If not,every time the data is received an overrun error is generated.130User’s Manual U14801EJ3V1UD