PIC16F688 Datasheet, PDF (51/174 Pages) Microchip Technology – 14-Pin Flash-Based, 8-Bit CMOS Microcontrollers with nanoWatt Technology

PIC16F688
6.0 TIMER1 MODULE WITH GATE
CONTROL
The PIC16F688 has a 16-bit timer. Figure 5-1 shows
the basic block diagram of the Timer1 module. Timer1
has the following features:
• 16-bit timer/counter (TMR1H:TMR1L)
• Readable and writable
• Internal or external clock selection
• Synchronous or asynchronous operation
• Interrupt-on-overflow from FFFFh to 0000h
• Wake-up upon overflow (Asynchronous mode)
• Optional external enable input
- Selectable gate source: T1G or C2 output
(T1GSS)
- Selectable gate polarity (T1GINV)
• Optional LP oscillator
The Timer1 Control register (T1CON), shown in
Register 6-1, is used to enable/disable Timer1 and
select the various features of the Timer1 module.
Note:
Additional information on timer modules is
available in the “PICmicro^® Mid-Range
MCU Family Reference Manual”
(DS33023).
FIGURE 6-1:
TIMER1 ON THE PIC16F688 BLOCK DIAGRAM
TMR1ON
TMR1GE
T1GINV
Set Flag bit
TMR1IF on
Overflow
TMR1⁽¹⁾
TMR1H
TMR1L
TMR1ON
TMR1GE
To C2 Comparator Module
TMR1 Clock
Synchronized
0
Clock Input
OSC1/T1CKI
OSC2/T1G
INTOSC
without CLKOUT
T1OSCEN
Oscillator
1
(2)
FOSC/4
Internal
Clock
T1SYNC
1
Prescaler
1, 2, 4, 8
0
2
T1CKPS<1:0>
TMR1CS
Synchronize
det
Sleep Input
1
C2OUT
0
Note 1:
2:
Timer1 increments on the rising edge.
ST Buffer is low power type when using LP oscillator or high-speed type when using
T1CKI.
T1GSS
 2004 Microchip Technology Inc.
Preliminary
DS41203B-page 49