PIC16F722-ESLASHML datasheet(116/302 Pages) MICROCHIP

116 / 302 page

PIC16F72X/PIC16LF72X

DS41341E-page 116

12.1

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 and increments on every instruction cycle.

When used with an external clock source, the module

can be used as either a timer or counter and incre-

ments on every selected edge of the external source.

Timer1 is enabled by configuring the TMR1ON and

TMR1GE bits in the T1CON and T1GCON registers,

respectively. Table 12-1 displays the Timer1 enable

selections.

12.2

Clock Source Selection

The TMR1CS<1:0> and T1OSCEN bits of the T1CON

Table 12-2 displays the clock source selections.

12.2.1

INTERNAL CLOCK SOURCE

When the internal clock source is selected the

TMR1H:TMR1L register pair will increment on multiples

of FOSC as determined by the Timer1 prescaler.

12.2.2

EXTERNAL CLOCK SOURCE

When the external clock source is selected, the Timer1

module may work as a timer or a counter.

When enabled to count, Timer1 is incremented on the

rising edge of the external clock input T1CKI or the

capacitive sensing oscillator signal. Either of these

external clock sources can be synchronized to the

microcontroller

system

clock

they

can

run

asynchronously.

When used as a timer with a clock oscillator, an

external 32.768 kHz crystal can be used in conjunction

with the dedicated internal oscillator circuit.

TABLE 12-1:

TIMER1 ENABLE

SELECTIONS

TMR1ON

TMR1GE

Timer1

Operation

Off

Always On

Count Enabled

Note:

In Counter mode, a falling edge must be

registered by the counter prior to the first

incrementing rising edge after any one or

more of the following conditions:

• Timer1 enabled after POR reset

• Write to TMR1H or TMR1L

• Timer1 is disabled

• Timer1 is disabled (TMR1ON = 0)

when T1CKI is high then Timer1 is

enabled (TMR1ON=1) when T1CKI is

low.

TABLE 12-2:

CLOCK SOURCE SELECTIONS

TMR1CS1

TMR1CS0

T1OSCEN

Clock Source

System Clock (FOSC)

Instruction Clock (FOSC/4)

Capacitive Sensing Oscillator

External Clocking on T1CKI Pin

Oscillator Circuit on T1OSI/T1OSO Pins

PIC16F722-E/ML Datasheet(PDF) 116 Page - Microchip Technology

PIC16F722-E/ML Datasheet(HTML) 116 Page - Microchip Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL