4.5.2.5.7 Caution about use of timer counters 0 and 1 .................................. 90
4.5.2.5.8 Caution about use of timer counters 0 and 1 when setting software
power down mode........................................................................... 91
4.5.3
Timer/counter 2 ......................................................................................... 92
4.5.3.1 Outline ...................................................................................................92
4.5.3.2 Timer 2 control register (T2CON) .......................................................... 92
4.5.3.3 Timer/counter 2 operation modes .......................................................... 93
4.5.3.3.1 16-bit auto reload mode .................................................................. 93
4.5.3.3.2 16-bit capture mode ........................................................................94
4.5.3.3.3 16-bit baud rate generator mode .................................................... 95
4.5.3.4 Timer/counter 2 detector circuit ............................................................. 97
4.5.3.4.1 T2(timer/counter 2 external clock detector) .................................... 97
4.5.3.4.2 T2EX(timer/counter 2 external flag input detector) ......................... 97
4.5.3.5 Timer/counter carry signal detector circuit ............................................. 98
4.6 Serial Port ......................................................................................................... 99
4.6.1
Outline ....................................................................................................... 99
4.6.2
Special function registers for serial port .................................................. 101
4.6.2.1 SCON .................................................................................................. 101
4.6.2.2 SBUF ...................................................................................................103
4.6.2.3 TCLK ...................................................................................................103
4.6.2.4 RCLK ...................................................................................................103
4.6.2.5 SMOD .................................................................................................. 104
4.6.2.6 SERR .................................................................................................. 105
4.6.3
Operating modes ..................................................................................... 106
4.6.3.1 Mode 0 .................................................................................................106
4.6.3.1.1 Outline........................................................................................... 106
4.6.3.1.2 Mode 0 baud rate .......................................................................... 106
4.6.3.1.3 Mode 0 transmit operation ............................................................ 106
4.6.3.1.4 Mode 0 receive operation ............................................................. 106
4.6.3.2 Mode 1 .................................................................................................. 110
4.6.3.2.1 Outline........................................................................................... 110
4.6.3.2.2 Mode 1 baud rate .......................................................................... 110
4.6.3.2.3 Mode 1 transmit operation ............................................................ 111
4.6.3.2.4 Mode 1 receive operation ............................................................. 111
4.6.3.2.5 Mode 1 UART error detection ....................................................... 112
4.6.3.3 Mode 2 .................................................................................................115
4.6.3.3.1 Outline........................................................................................... 115
4.6.3.3.2 Mode 2 baud rate .......................................................................... 115
4.6.3.3.3 Mode 2 transmit operation ............................................................ 115
4.6.3.3.4 Mode 2 receive operation ............................................................. 115
4.6.3.3.5 Mode 2 UART error detection ....................................................... 116
4.6.3.4 Mode 3 .................................................................................................119
4.6.3.4.1 Outline........................................................................................... 119
4.6.3.4.2 Mode 3 baud rate .......................................................................... 119
4.6.3.4.3 Mode 3 transmit operation ............................................................ 120
4.6.3.4.4 Mode 3 receive operation. ............................................................ 120
4.6.3.4.5 Mode 3 UART error detection ....................................................... 121
4.6.4
Serial port application examples .............................................................. 124
4.6.4.1 I/O extension ....................................................................................... 124