![](http://datasheet.mmic.net.cn/30000/M30956FKTGP_datasheet_2359453/M30956FKTGP_234.png)
16.1.1.3 Serial Data Logic Inverse
When the UiLCH bit in the UiC1 register is set to 1 (inverted), data logic written in the UiTB register is inverted
for transmit operation. The UiRB register returns inverted logic of receive data when read.
Figure 16.14 shows
an example of serial data logic inverse operation.
Figure 16.14
Serial Data Logic Inverse
16.1.1.4 CTS/RTS Function
When the CTS function is used, the transmit/receive operation starts when a low-level (“L”) signal is applied to
the CTSi pin (i = 0 to 4). When a high-level (“H”) signal is applied to the CTSi pin during transmitting/
receiving, the transmit/receive operation stops after the ongoing transmit/receive operation is completed. To use
the CTS function, select the I/O port with the function select register, set the CRD bit in the UiC0 register to 0
(CTS function enabled), and set the CRS bit in the UiC0 register to 0 (CTS function selected).
When the RTS function is used, the RTSi pin outputs an “H” at the first falling edge of the clock input to the
CLKi pin, and outputs an “L” under the following conditions.
The RI bit in the UiC1 register is 0 (no data in the UiRB register).
The TE bit in the UiC1 register is set to 1 (transmit operation enabled).
The RE bit in the UiC1 register is set to 1 (receive operation enabled).
The TI bit in the UiC1 register is 0 (data in the UiTB register).
To use the RTS function, select the RTSi pin with the function select register.
Serial clock
(1) When the UiLCH bit in the UiC1 register (i = 0 to 4) is set to 0 (not inverted)
D0
D1
D3
D4
D5
D6
D7
D2
(2) When the UiLCH bit is set to 1 (inverted)
TXDi
(not inverted)
NOTE:
1.The above applies when the CKPOL bit in the UiC0 register is set to 0 (transmit data is output at the
falling edge of the serial clock and received data is input at the rising edge), and the UFORM bit in the
UiC0 register is set to 0 (LSB first).
"H"
"L"
"H"
"L"
D0
D1
D3
D4
D5
D6
D7
D2
Serial clock
TXDi
(inverted)
"H"
"L"
"H"
"L"