Page 231 - Making PIC Microcontroller Instruments and Controllers

22a CREA I|O ACCUR/ITE TNTERVALS W|lH fltf,ERs tHE lllETROllOlllES

Timer2

Timer2 is discussed on page 59 in the datasheet.
Basic description: Timer2 has 8 bits, and both a pre- and postscalar. It uses the
internal clock only and shares the prescalar with the watchdog timer. It can be tumed
on and off but cannotbe used as a counter lt cannot be used as a counter because it does
not have a pin on which it can receive the counter signals.
Timer2 i s an 8-bit timer with both a prescalar and a postscaiar. The prescalar can be as
greatas16,aodthepostscalarcanb€asgreatas16,foratotalscalingofl6x16=256,
which is the same as for Timero. However not d]l 256 scalings are available as they are
for Timeo Oecause the prescalar can only be set to l, 4, or 16).
The Timer2 is identilied as register TMR2.
The control registers for Timer2 are INTCON, T2CON, PIEI, and PIR1. The biis in
these registers control Timer2 as foilows:
T2CON.1 and T2CON.0 set the value of the prescalar as tbllowsl

Bil value Prescalar value selected
00 I, No prescalar is used

01 4
1x

The postscalar is specified by the 4 bits from T2CON.6 toT2C0N.3 as follows:

Bit value Postscalar value selected
0000 l, No prescalar is used

0001 2
0010 3
0011 4

0100 s
0101 6
0ll0 1
o l l t 8

1000 9
1001 r0
l0l0 l l

1011 t2