Intel 8XC251SP, 8XC251SA, 8XC251SQ manual Timer 2 Generated Baud Rates, Oscillator Baud Rate, RCAP2H

8XC251SA, SB, SP, SQ USER’S MANUAL

Note that timer 2 increments every state time (2TOSC) when it is in the baud rate generator mode. In the baud rate formula that follows, “RCAP2H, RCAP2L” denotes the contents of RCAP2H and RCAP2L taken as a 16-bit unsigned integer:

FOSC

Serial I/O Modes 1 and 3 Baud Rates = ------------------------------------------------------------------------------------------------------

32 × [65536 – (RCAP2H, RCAP2L ) ]

NOTE

When timer 2 is configured as a timer and is in baud rate generator mode, do not read or write the TH2 or TL2 registers. The timer is being incremented every state time, and the results of a read or write may not be accurate. In addition, you may read, but not write to, the RCAP2 registers; a write may overlap a reload and cause write and/or reload errors.

Table 10-6 lists commonly used baud rates and shows how they are generated by timer 2.

Table 10-6. Timer 2 Generated Baud Rates

	Oscillator
Baud Rate	Frequency	RCAP2H	RCAP2L
	(FOSC)
375.0 Kbaud	12 MHz	FFH	FFH
9.6 Kbaud	12 MHz	FFH	D9H
4.8 Kbaud	12 MHz	FFH	B2H
2.4 Kbaud	12 MHz	FFH	64H
1.2 Kbaud	12 MHz	FEH	C8H
300.0 baud	12 MHz	FBH	1EH
110.0 baud	12 MHz	F2H	AFH
300.0 baud	6 MHz	FDH	8FH
110.0 baud	6 MHz	F9H	57H

10-14