M16C30_02 Datasheet, PDF (118/178 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

Clock asynchronous serial I/O (UART) mode
Mitsubishi microcomputers
M16C / 30 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
(c) TxD, RxD I/O polarity reverse function (UART2)
This function is to reverse TXD pin output and RXD pin input. The level of any data to be input or output
(including the start bit, stop bit(s), and parity bit) is reversed. Set this function to “0” (not to reverse) for
usual use.
(d) Bus collision detection function (UART2)
This function is to sample the output level of the TXD pin and the input level of the RXD pin at the rising
edge of the transfer clock; if their values are different, then an interrupt request occurs. Figure 1.16.21
shows the example of detection timing of a bus collision (in UART mode).
Transfer clock ^{“H”}
“L”
TxD2 ^{“H”}
ST
“L”
RxD2 ^{“H”}
ST
“L”
Bus collision detection _{“1”}
interrupt request signal _{“0”}
Bus collision detection _{“1”}
interrupt request bit _{“0”}
Figure 1.16.21. Detection timing of a bus collision (in UART mode)
SP
SP
ST : Start bit
SP : Stop bit
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