Datasheet

PIC18F66K80 FAMILY
DS39977F-page 222  2010-2012 Microchip Technology Inc.
15.2 Timer2 Interrupt
Timer2 can also generate an optional device interrupt.
The Timer2 output signal (TMR2 to PR2 match) provides
the input for the four-bit output counter/postscaler. This
counter generates the TMR2 match interrupt flag, which
is latched in TMR2IF (PIR1<1>). The interrupt is enabled
by setting the TMR2 Match Interrupt Enable bit, TMR2IE
(PIE1<1>).
A range of 16 postscaler options (from 1:1 through 1:16
inclusive) can be selected with the postscaler control
bits, T2OUTPS<3:0> (T2CON<6:3>).
15.3 Timer2 Output
The unscaled output of TMR2 is available primarily to
the ECCP modules, where it is used as a time base for
operations in PWM mode.
Timer2 can optionally be used as the shift clock source
for the MSSP module operating in SPI mode.
Additional information is provided in
Section 21.0
“Master Synchronous Serial Port (MSSP) Module”
.
FIGURE 15-1: TIMER2 BLOCK DIAGRAM
TABLE 15-1: REGISTERS ASSOCIATED WITH TIMER2 AS A TIMER/COUNTER
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF
PIR1
PSPIF ADIF RC1IF TX1IF SSPIF TMR1GIF TMR2IF TMR1IF
PIE1
PSPIE ADIE RC1IE TX1IE SSPIE TMR1GIE TMR2IE TMR1IE
IPR1
PSPIP ADIP RC1IP TX1IP SSPIP TMR1GIP TMR2IP TMR1IP
TMR2 Timer2 Register
T2CON
— T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 TMR2ON T2CKPS1 T2CKPS0
PR2 Timer2 Period Register
PMD1
PSPMD CTMUMD ADCMD TMR4MD TMR3MD TMR2MD TMR1MD TMR0MD
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the Timer2 module.
Comparator
TMR2 Output
TMR2
Postscaler
Prescaler
PR2
2
F
OSC/4
1:1 to 1:16
1:1, 1:4, 1:16
4
T2OUTPS<3:0>
T2CKPS<1:0>
Set TMR2IF
Internal Data Bus
8
Reset
TMR2/PR2
8
8
(to PWM or MSSP)
Match