INTERNAL SPECIFICATIONS95XTAL 1 ÷12 S3DETECTORT2[PORT 1.0]Q0------Q7TL28 BITCRCAP2LQ0------Q7TH28 BITCRCAP2HDETECTORT2EX[PORT 1.1]TR2EXEN2DETECTORDETECTORTF2EXF2TIMER 2INTERRUPTRCLK=0TCLK=0CP/ RL2=1C/ T2Figure 4-21 Timer/counter 2 16-bit capture mode circuit4.5.3.3.3 16-bit baud rate generator modeThe 16-bit baud rate generator mode is set by making the connections shown in Figure 4-22with the following timer 2 control register (T2CON) bit conditions, viz.RCLK+TCLK=1.Timer/counter 2 commences to operate in the following way when 16-bit baud rate generatormode is set.Timer/counter 2 is put into 16-bit auto reload mode. When timer/counter 2 generates a carrysignal, the reload data in the RCAP2L and RCAP2H registers is preset in the timer/counter2 TL2 and TH2 and the timer/counter commences to count from that preset value. The carrysignal is passed to a serial port.The timer/counter 2 carry signal activates the serial port receive circuit when RCLK 1, andactivates the transmit circuit when TCLK=1. Note, however, that the serial port can use theseclocks only when the serial port is in mode 1 and 3.When in this mode, the timer/counter 2 carry signal is not set in internal timer flag 2 (TF2).But since the change in level (from “1” to “0”) of the signal applied to the T2EX pin (bit 1 ofport 1) is set in external timer flag 2, the T2EX pin can be used for ordinary external interruptinput pin. If an interrupt routine is commenced, the EXF2 flag must be reset to “0” by software.Since timer/counter 2 is operated at 1/2 of the XTAL1·2 clock if the internal clock is used inthis mode, only undefined data will be read from the timer/counter 2 TL2 and TH2 by software.Correct data, however, is read from the RCAP2L and RCAP2H registers.
