PIC16F688-E/SL View Datasheet(PDF) - Microchip Technology

Part Name

Description

Manufacturer

PIC16F688-E/SL

14-Pin Flash-Based, 8-Bit CMOS Microcontrollers with nanoWatt Technology

Microchip Technology 

PIC16F688

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)

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

Clock Source

FOSC/4

T1CKI pin

TMR1GE

T1GINV

Set flag bit

TMR1IF on

Overflow

TMR1(2)

TMR1H

EN

TMR1L

TMR1ON

To C2 Comparator Module

Timer1 Clock

Synchronized

0

clock input

OSC1/T1CKI

OSC2/T1G

Oscillator

INTOSC

Without CLKOUT

T1OSCEN

1

(1)

FOSC/4

Internal

Clock

T1SYNC

1

Prescaler

1, 2, 4, 8

0

2

T1CKPS<1:0>

TMR1CS

Synchronize(3)

det

1

C2OUT

0

T1GSS

Note 1:

2:

3:

ST Buffer is low power type when using LP oscillator, or high speed type when using T1CKI.

Timer1 register increments on rising edge.

Synchronize does not operate while in Sleep.

DS41203D-page 48

© 2007 Microchip Technology Inc.

Share Link: