PIC18F2220/2320/4220/4320
FIGURE 11-1:
TIMER0 BLOCK DIAGRAM IN 8-BIT MODE
Data Bus
8
FOSC/4
0
1
RA4/T0CKI/C1OUT
pin
0
Sync with
Internal
Clocks
TMR0
Programmable
Prescaler
1
(2 TCY delay)
T0SE
3
PSA
Set Interrupt
Flag bit TMR0IF
on Overflow
T0PS2, T0PS1, T0PS0
T0CS
Note: Upon Reset, Timer0 is enabled in 8-bit mode with clock input from T0CKI maximum prescale.
FIGURE 11-2:
TIMER0 BLOCK DIAGRAM IN 16-BIT MODE
RA4/T0CKI/C1OUT
pin
FOSC/4
0
1
0
1
Sync with
Internal
Clocks
Set Interrupt
Flag bit TMR0IF
on Overflow
TMR0
High Byte
TMR0L
Programmable
Prescaler
8
(2 TCY delay)
T0SE
3
Read TMR0L
Write TMR0L
T0PS2, T0PS1, T0PS0
T0CS
PSA
8
8
TMR0H
8
Data Bus<7:0>
Note: Upon Reset, Timer0 is enabled in 8-bit mode with clock input from T0CKI maximum prescale.
DS39599C-page 118
2003 Microchip Technology Inc.