PIC12F635-E/MD MICROCHIP [Microchip Technology], PIC12F635-E/MD Datasheet - Page 66

• Manufacturer Part Number: PIC12F635-E/MD
• Description: 8/14-Pin, Flash-Based 8-Bit CMOS Microcontrollers with nanoWatt Technology
• Manufacturer: MICROCHIP [Microchip Technology]

PIC12F635/PIC16F636/639
6.0
The Timer1 module is a 16-bit timer/counter with the
following features:
• 16-bit timer/counter register pair (TMR1H:TMR1L)
• Programmable internal or external clock source
• 3-bit prescaler
• Optional LP oscillator
• Synchronous or asynchronous operation
• Timer1 gate (count enable) via comparator or
• Interrupt on overflow
• Wake-up on overflow (external clock,
• Comparator output synchronization to Timer1
Figure 6-1 is a block diagram of the Timer1 module.
6.1
The Timer1 module is a 16-bit incrementing counter
which is accessed through the TMR1H:TMR1L register
pair. Writes to TMR1H or TMR1L directly update the
counter.
When used with an internal clock source, the module is
a timer. When used with an external clock source, the
module can be used as either a timer or counter.
6.2
The TMR1CS bit of the T1CON register is used to select
the clock source. When TMR1CS = 0, the clock source
is F
supplied externally.
DS41232D-page 64
F
T1CKI pin
T1LPOSC
T1G pin
Asynchronous mode only)
clock
OSC
Source
Clock
OSC
/4
/4. When TMR1CS = 1, the clock source is
TIMER1 MODULE WITH GATE
CONTROL
Timer1 Operation
Clock Source Selection
T1OSCEN
x
x
1
INTOSCIO
FOSC
Mode
LP or
xxx
T1CS
x
1
© 2007 Microchip Technology Inc.