CHAPTER 11 SERIAL INTERFACE UART6User’s Manual U16898EJ3V0UD19211.4 Operation of Serial Interface UART6Serial interface UART6 has the following two modes.• Operation stop mode• Asynchronous serial interface (UART) mode11.4.1 Operation stop modeIn this mode, serial communication cannot be executed; therefore, the power consumption can be reduced. Inaddition, the pins can be used as ordinary port pins in this mode. To set the operation stop mode, clear bits 7, 6, and5 (POWER6, TXE6, and RXE6) of ASIM6 to 0.(1) Register usedThe operation stop mode is set by asynchronous serial interface operation mode register 6 (ASIM6).ASIM6 can be set by a 1-bit or 8-bit memory manipulation instruction.Reset signal generation sets this register to 01H.Address: FF90H After reset: 01H R/WSymbol <7> <6> <5> 4 3 2 1 0ASIM6 POWER6 TXE6 RXE6 PS61 PS60 CL6 SL6 ISRM6POWER6 Enabling/disabling operation of internal operation clock0Note 1 Disable operation of the internal operation clock (fix the clock to low level) and asynchronouslyreset the internal circuitNote 2.TXE6 Enabling/disabling transmission0 Disable transmission operation (synchronously reset the transmission circuit).RXE6 Enabling/disabling reception0 Disable reception (synchronously reset the reception circuit).Notes 1. The output of the T XD6 pin goes high and the input from the R XD6 pin is fixed to high level whenPOWER6 = 0 during a transmission.2. Asynchronous serial interface reception error status register 6 (ASIS6), asynchronous serial interfacetransmission status register 6 (ASIF6), bit 7 (SBRF6) and bit 6 (SBRT6) of asynchronous serialinterface control register 6 (ASICL6), and receive buffer register 6 (RXB6) are reset.Caution Clear POWER6 to 0 after clearing TXE6 and RXE6 to 0 to set the operation stop mode.To start the operation, set POWER6 to 1, and then set TXE6 and RXE6 to 1.Remark To use the RxD6/P44 and TxD6/INTP1/P43 pins as general-purpose port pins, see CHAPTER 4 PORTFUNCTIONS.