M306H7MG-XXXFP Datasheet, PDF (114/329 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER with DATA ACQUISITION CONTROLLER

M306H7MG-XXXFP/MC-XXXFP/FGFP
10. SERIAL I/O
10.3.2 Serial Data Logic Switching Function
The data written to the UiTB register has its logic reversed before being transmitted. Similarly, the received
data has its logic reversed when read from the UiRB register. Figure 10.18 shows serial data logic.
(1) When the UiC1 register's UiLCH bit = 0 (no reverse)
Transfer clock ^{“H”}
“L”
TxDi “H”
(no reverse) _{“L”}
ST D0 D1 D2 D3 D4 D5 D6 D7 P SP
(2) When the UiC1 register's UiLCH bit = 1 (reverse)
Transfer clock ^{“H”}
“L”
TxDi ^{“H”}
(reverse) _{“L”}
ST D0 D1 D2 D3 D4 D5 D6 D7 P SP
ST : Start bit
P : Parity bit
SP : Stop bit
i = 0 to 2
Note: This applies to the case where the UiC0 register’s CKPOL bit = 0
(transmit data output at the falling edge of the transfer clock), the
UiC0 register's UFORM bit = 0 (LSB first), the UiMR register's
STPS bit = 0 (1 stop bit) and UiMR register's PRYE bit = 1 (parity
enabled).
Figure 10.18 Serial Data Logic Switching
10.3.3 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 10.19 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”
ST D0 D1 D2 D3 D4 D5 D6 D7 P SP
RxDi ^{“H”}
(reverse) ^{“L”}
ST D0 D1 D2 D3 D4 D5 D6 D7 P SP
ST : Start bit
P : Parity bit
SP : Stop bit
i = 0 to 2
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).
Figure 10.19 TXD and RXD I/O Polarity Inverse
Rev.2.10 Oct 25, 2006 Page 114 of 326
REJ03B0152-0210