M16C30P_07 Datasheet, PDF (153/317 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/30 SERIES

M16C/30P Group
15. Serial Interface
15.1.1.7 CTS/RTS Function
When the CTS function is used transmit and receive operation start when “L” is applied to the CTSi/RTSi (i=0
to 2) pin. Transmit and receive operation begins when the CTSi/RTSi pin is held “L”. If the “L” signal is
switched to “H” during a transmit or receive 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 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
15.1.1.8 CTS/RTS Separate Function (UART0)
This function separates CTS0/RTS0, outputs RTS0 from the P6_0 pin, and accepts as input the CTS0 from the
P6_4 pin. To use this function, set the register bits as shown below.
• CRD bit in U0C0 register = 0 (enable CTS/RTS of UART0)
• CRS bit in U0C0 register = 1 (output RTS of UART0)
• CRD bit in U1C0 register = 0 (enable CTS/RTS of UART1)
• CRS bit in U1C0 register = 0 (input CTS of UART1)
• RCSP bit in UCON register = 1 (inputs CTS0 from the P6_4 pin)
• CLKMD1 bit in UCON register = 0 (CLKS1 not used)
Note that when using the CTS/RTS separate function, CTS/RTS of UART1 separate function cannot be used.
Microcomputer
TXD0 (P6_3)
RXD0 (P6_2)
CLK0 (P6_1)
RTS0 (P6_0)
CTS0 (P6_4)
IC
IN
OUT
CLK
CTS
RTS
Figure 15.17 CTS/RTS Separate Function
Rev.1.22 Mar 29, 2007 Page 137 of 291
REJ09B0179-0122