Datasheet

PIC16C712/716
DS41106C-page 32  1999-2013 Microchip Technology Inc.
FIGURE 5-2: TIMER1 BLOCK DIAGRAM
5.2 Timer1 Module and PORTB
Operation
When Timer1 is configured as timer running from the
main oscillator, PORTB<2:1> operate as normal I/O
lines. When Timer1 is configured to function as a
counter however, the clock source selection may affect
the operation of PORTB<2:1>. Multiplexing details of
the Timer1 clock selection on PORTB are shown in
Figure 3-4 and Figure 3-5.
The clock source for Timer1 in the Counter mode can
be from one of the following:
1. External circuit connected to the RB1/T1OSO/
T1CKI pin
2. Firmware controlled DATACCP<0> bit, DT1CKI
3. Timer1 oscillator
Table 5-1 shows the details of Timer1 mode selections,
control bit settings, TMR1 and PORTB operations.
TMR1H
TMR1L
T1OSC
T1SYNC
TMR1CS
T1CKPS1:T1CKPS0
Sleep input
T1OSCEN
Enable
Oscillator
(1)
FOSC/4
Internal
Clock
TMR1ON
on/off
Prescaler
1, 2, 4, 8
Synchronize
det
1
0
0
1
Synchronized
clock input
2
RB1/T1OSO/T1CKI
RB2/T1OSI
Note 1: When the T1OSCEN bit is cleared, the inverter and feedback resistor are turned off. This eliminates power drain.
Set flag bit
TMR1IF on
Overflow
TMR1