M306V8FJFP Datasheet, PDF (147/365 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

M306V8FJFP
(e) TxD and RxD I/O Polarity Inverse Function
This function inverses the polarities of the TXDi pin output and RXDi pin input. The logic levels of all
input/output data (including the start, stop and parity bits) are inversed. Figure 11.19 shows the TXD
pin output and RXD pin input polarity inverse.
(1) When the UiMR register's IOPOL bit = 0 (no reverse)
Transfer clock ^{“H”}
“L”
TxDi “H”
(no reverse) “L”
ST D0 D1 D2 D3 D4 D5 D6 D7 P SP
RxDi ^{“H”}
(no reverse) “L”
ST D0 D1 D2 D3 D4 D5 D6 D7 P SP
(2) When the UiMR register's IOPOL bit = 1 (reverse)
Transfer clock ^{“H”}
“L”
TxDi “H”
(reverse) “L”
RxDi
(reverse)
“H”
“L”
ST D0 D1 D2 D3 D4 D5 D6 D7 P
ST D0 D1 D2 D3 D4 D5 D6 D7 P
Note: This applies to the case where the UiC0 register's UFORM bit = 0
(LSB first), the UiMR register's STPS bit = 0 (1 stop bit) and the
UiMR register's PRYE bit = 1 (parity enabled).
SP
SP
ST : Start bit
P : Parity bit
SP : Stop bit
i = 0 to 2
Figure 11.19. TXD and RXD I/O Polarity Inverse
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(f) CTS/RTS Function
_______
________ ________
When the CTS function is used transmit operation start when “L” is applied to the CTSi/RTSi (i=0 to 2)
________ ________
pin. Transmit operation begins when the CTSi/RTSi pin is held “L”. If the “L” signal is switched to “H”
during a transmit operation, the operation stops before the next data.
_______
________ ________
When the RTS function is used, the CTSi/RTSi pin outputs on “L” signal when the microcomputer is
ready to receive. The output level becomes “H” on the first falling edge of the CLKi pin.
_______ _______
• CRD bit in UiC0 register = 1 (disable CTS/RTS function of UART0)
________ ________
CTSi/RTSi pin is programmable I/O function
_______
________ ________
_______
• CRD bit = 0, CRS bit = 0 (CTS function is selected) CTSi/RTSi pin is CTS function
_______
________ ________
_______
• CRD bit = 0, CRS bit = 1 (RTS function is selected) CTSi/RTSi pin is RTS function
Rev.1.31 Apr 18, 2005 page 147 of 363
REJ03B0082-0131