Datasheet

 2011 Microchip Technology Inc. DS39932D-page 209
PIC18F46J11 FAMILY
FIGURE 13-4: TIMER1 GATE COUNT ENABLE MODE
13.8.2 TIMER1 GATE SOURCE
SELECTION
The Timer1 gate source can be selected from one of
four different sources. Source selection is controlled by
the T1GSSx bits of the T1GCON register. The polarity
for each available source is also selectable. Polarity
selection is controlled by the T1GPOL bit of the
T1GCON register.
TABLE 13-4: TIMER1 GATE SOURCES
13.8.2.1 T1G Pin Gate Operation
The T1G pin is one source for Timer1 gate control. It
can be used to supply an external source to the Timer1
gate circuitry.
13.8.2.2 Timer0 Overflow Gate Operation
When Timer0 increments from FFh to 00h, a
low-to-high pulse will automatically be generated and
internally supplied to the Timer1 gate circuitry.
13.8.2.3 Timer2 Match Gate Operation
The TMR2 register will increment until it matches the
value in the PR2 register. On the very next increment
cycle, TMR2 will be reset to 00h. When this Reset
occurs, a low-to-high pulse will automatically be
generated and internally supplied to the Timer1 gate
circuitry.
The pulse remains high for one instruction cycle and
returns to low until the next match.
When T1GPOL = 1, Timer1 increments for a single
instruction cycle following TMR2 matching PR2.
With T1GPOL = 0, Timer1 increments except during
the cycle following the match.
TMR1GE
T1GPOL
T1G_IN
T1CKI
T1GVAL
Timer1
N
N + 1 N + 2 N + 3 N + 4
T1GSS<1:0> Timer1 Gate Source
00 Timer1 Gate Pin
01 Overflow of Timer0
(TMR0 increments from FFh to 00h)
10 TMR2 to Match PR2
(TMR2 increments to match PR2)