M16C6S_09 Datasheet, PDF (116/208 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

M16C/6S Group
UART Mode
_______ _______
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
_______ _______
(d) CTS/RTS Separate Function (UART0)
_______ _______
_______
_______
This function separates CTS0/RTS0, outputs RTS0 from the P60 pin, and accepts as input the CTS0
from the P64 pin. To use this function, set the register bits as shown below.
_______ _______
• U0C0 register's CRD bit = 0 (enables UART0 CTS/RTS)
_______
• U0C0 register's CRS bit = 1 (outputs UART0 RTS)
_______ _______
• U1C0 register's CRD bit = 0 (enables UART1 CTS/RTS)
_______
• U1C0 register's CRS bit = 0 (inputs UART1 CTS)
_______
• UCON register's RCSP bit = 1 (inputs CTS0 from the P64 pin)
• UCON register's CLKMD1 bit = 0 (CLKS1 not used)
_______ _______
_______ _______
Note that when using the CTS/RTS separate function, UART1 CTS/RTS separate function cannot be
used.
Microcomputer
TXD0 (P63)
RXD0 (P62)
IC
IN
OUT
RTS0 (P60)
CTS0 (P64)
_______ _______
Figure 1.15.6. CTS/RTS Separate Function
CTS
RTS
Rev.5.01 Dec 10, 2009 page 116 of 201
REJ03B0014-0501