NEC PD78058FY(A) - Manual (Page 460)

460
CHAPTER 19 SERIAL INTERFACE CHANNEL 2
(3) UART mode cautions
(a) If bit 7 (TXE) of the asynchronous serial interface mode register (ASIM) is cleared to (0) during
transmission and sending operation is halt, be sure to set the transmit shift register (TXS) to FFH, then
set TXE to 1 before executing the next transmission.
(b) If bit 6 (RXE) of ASIM is cleared (0) during reception and receiving operation is halt, the status of the receive
buffer register (RXB) and whether or not a receive completion interrupt (INTSR) is generated differ
depending on the timing. The timing is shown in Figure 19-11.
Figure 19-11. Receive Buffer Register (RXB) Status and Receive Completion Interrupt
Request (INTSR) Generation When Receiving Is Terminated
Parity RxD Pin
RXB
INTSR
<3> <1>
<2>
When RXE is set to 0 at a time indicated by <1>, RXB holds the previous data and does not generate INTSR.
When RXE is set to 0 at a time indicated by <2>, RXB renews the data and does not generate INTSR.
When RXE is set to 0 at a time indicated by <3>, RXB renews the data and generates INTSR.