Intel 8XC251SA manual Selecting the Baud Rate Generators, Rclck Tclck, Receiver Transmitter Bit

SERIAL I/O PORT

You may configure timer 2 as a timer or a counter. In most applications, it is configured for timer operation (i.e., the C/T2# bit is clear in the T2CON register).

Table 10-5. Selecting the Baud Rate Generator(s)

RCLCK	TCLCK	Receiver	Transmitter
Bit	Bit	Baud Rate Generator	Baud Rate Generator
0	0	Timer 1	Timer 1
0	1	Timer 1	Timer 2
1	0	Timer 2	Timer 1
1	1	Timer 2	Timer 2

	Note:
	Oscillator frequency
	is divided by 2, not 12.
XTAL1			2	0
					1
T2
		C/T2#				TR2

Timer 1	2	0
Overflow		1
	SMOD1
TH2	TL2	1
(8 Bits)	(8 Bits)
		0
		RCLCK
		1
		0
RCAP2H RCAP2L
		TCLCK

16

16

RX

Clock

TX

Clock

T2EX	EXF2	Interrupt
		Request
	EXEN2

Note availability of additional external interrupt.

A4120-01

Figure 10-5. Timer 2 in Baud Rate Generator Mode

10-13