M16C26 Datasheet, PDF (142/239 Pages) Renesas Technology Corp – 16-BIT CMOS SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/20 SERIES

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Preliminary Specifications Rev. 0.9
Specifications in this manual are tentative
Clock Asynchronous Serial I/O (UART) Mode
and
subject to change.
SINGLE-CHIP 16-BIT
M16C/26 Group
CMOS MICROCOMPUTER
(b) TxD, RxD I/O polarity reverse function (UART2)
This function reverses/inverts 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 re-
versed/inverted) for normal use.
(c) Bus collision detection function (UART2)
This function samples 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 1.15.23
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 1.15.23. Detection timing of a bus collision (in UART mode)
SP
SP
ST : Start bit
SP : Stop bit
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Renesas Technology Corp.