PIC16LF1507 Datasheet, PDF (135/266 Pages) Microchip Technology – 20-Pin Flash, 8-Bit Microcontrollers

PIC16(L)F1507
16.0 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 16-1 is a block diagram of the Timer0 module.
16.1 Timer0 Operation
The Timer0 module can be used as either an 8-bit timer
or an 8-bit counter.
16.1.1 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_REG 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.
16.1.2 8-BIT COUNTER MODE
In 8-Bit Counter mode, the Timer0 module will increment
on every rising or falling edge of the T0CKI pin.
8-Bit Counter mode using the T0CKI pin is selected by
setting the TMR0CS bit in the OPTION_REG 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_REG register.
FIGURE 16-1:
BLOCK DIAGRAM OF THE TIMER0
FOSC/4
T0CKI
0
1
TMR0SE _TMR0CS
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>
DS41586A-page 135
Preliminary
 2011 Microchip Technology Inc.