PIC16F684T-E Datasheet, PDF (49/192 Pages) Microchip Technology – 14-Pin, Flash-Based 8-Bit CMOS Microcontrollers with nanoWatt Technology

PIC16F684
6.0 TIMER1 MODULE WITH GATE
CONTROL
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
T1G pin
• Interrupt on overflow
• Wake-up on overflow (external clock,
Asynchronous mode only)
• Time base for the Capture/Compare function
• Special Event Trigger (with ECCP)
• Comparator output synchronization to Timer1
clock
Figure 6-1 is a block diagram of the Timer1 module.
FIGURE 6-1:
TIMER1 BLOCK DIAGRAM
6.1 Timer1 Operation
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 Clock Source Selection
The TMR1CS bit of the T1CON register is used to select
the clock source. When TMR1CS = 0, the clock source
is FOSC/4. When TMR1CS = 1, the clock source is
supplied externally.
Clock Source
FOSC/4
T1CKI pin
TMR1CS
0
1
TMR1GE
T1GINV
Set flag bit
TMR1IF on
Overflow
TMR1⁽¹⁾
TMR1H
EN
TMR1L
TMR1ON
To C2 Comparator Module
Timer1 Clock
Synchronized
0
clock input
OSC1/T1CKI
OSC2/T1G
Oscillator
T1OSCEN
FOSC = 100
FOSC = 000
Sleep
1
*
1
FOSC/4
Internal ⁰
Clock
T1SYNC
Prescaler
1, 2, 4, 8
2
T1CKPS<1:0>
TMR1CS
Synchronize
det⁽²⁾
1
C2OUT
0
T1GSS
*
Note 1:
2:
ST Buffer is low power type when using LP osc, or high speed type when using T1CKI.
Timer1 register increments on rising edge.
Synchronize does not operate while in Sleep.
© 2007 Microchip Technology Inc.
DS41202F-page 47