PIC12F1822T-I/SL View Datasheet(PDF) - Microchip Technology

Part Name

Description

Manufacturer

PIC12F1822T-I/SL

8/14-Pin Flash Microcontrollers with nanoWatt XLP Technology

Microchip Technology 

PIC12F/LF1822/16F/LF1823

19.0 TIMER0 MODULE

The Timer0 module is an 8-bit timer/counter with the

following features:

• 8-bit timer/counter register (TMR0)

• 8-bit prescaler (independent of Watchdog Timer)

• Programmable internal or external clock source

• Programmable external clock edge selection

• Interrupt on overflow

• TMR0 can be used to gate Timer1

Figure 19-1 is a block diagram of the Timer0 module.

19.1 Timer0 Operation

The Timer0 module can be used as either an 8-bit timer

or an 8-bit counter.

19.1.1 8-BIT TIMER MODE

The Timer0 module will increment every instruction

cycle, if used without a prescaler. 8-Bit Timer mode is

selected by clearing the TMR0CS bit of the OPTION

register.

When TMR0 is written, the increment is inhibited for

two instruction cycles immediately following the write.

Note:

The value written to the TMR0 register can

be adjusted, in order to account for the two

instruction cycle delay when TMR0 is

written.

19.1.2 8-BIT COUNTER MODE

In 8-bit Counter mode, the Timer0 module will increment

on every rising or falling edge of the T0CKI pin or the

Capacitive Sensing Oscillator (CPSCLK) signal.

8-Bit Counter mode using the T0CKI pin is selected by

setting the TMR0CS bit in the OPTION register to ‘1’

and resetting the T0XCS bit in the CPSCON0 register to

‘0’.

8-Bit Counter mode using the Capacitive Sensing

Oscillator (CPSCLK) signal is selected by setting the

TMR0CS bit in the OPTION register to ‘1’ and setting

the T0XCS bit in the CPSCON0 register to ‘1’.

The rising or falling transition of the incrementing edge

for either input source is determined by the TMR0SE bit

in the OPTION register.

FIGURE 19-1:

BLOCK DIAGRAM OF THE TIMER0

FOSC/4

0

T0CKI

0

1

From CPSCLK

1 TMR0SE TMR0CS

T0XCS

8-bit

Prescaler

1

0

PSA

Sync

2 TCY

Data Bus

8

TMR0

Set Flag bit TMR0IF

on Overflow

Overflow to Timer1

8

PS<2:0>

 2010 Microchip Technology Inc.

Preliminary

DS41413A-page 169

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