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Is it possible to use both CTS and RTS functions?

Latest Updated:03/29/2013


Is it possible to use both CTS and RTS functions?


Yes, it is possible to use both functions.

When CTS signal and RTS signal of the serial interfaces (UART) are assigned to multiple pins, each signal can be assigned to a different pin.
Each group has different usable channels of UART:

  1. R32C/116, R32C/117, and R32C/118 Groups for the 144-pin package; and
    R32C/116A, R32C/117A, and R32C/118A Groups for the 144-pin or 176-pin package
    → Usable channels: UART3, UART6, UART7, and UART8
  2. R32C/120, R32C/121, R32C/142, and R32C/145 Groups for the 100-pin package; and
    R32C/151, R32C/152, R32C/153, R32C/156, and R32C/157 Groups for the 144-pin package
    → Usable channels: UART3 and UART4
  3. R32C/160 and R32C/161 Groups for the 80-pin package
    → Usable channel: UART4

A configuration example when using UART3 in R32C/116 Group

   p9_2s: 03h /*Port P9_2 function select register: TXD3*/ 
   pd9_2: 1 
   p9_3s: 03h /*Port P9_3 function select register: RTS3*/ 
   pd9_3: 1 
   ifs06: 0 /*P4 in operation*/ 
   pd4_0: 0 /*P4_0 port direction bit: input (CTS3)*/
   pd4_2: 0 /*P4_2 port direction bit: input (RXD3)*/

*Note: Port P9_1 cannot be used as RXD3 in this configuration example.

Suitable Products
R32C/160, R32C/161
R32C/151, R32C/152, R32C/153, R32C/156, R32C/157
R32C/142, R32C/145
R32C/120, R32C/121
R32C/116A, R32C/117A, R32C/118A
R32C/116, R32C/117, R32C/118