Datasheet

© 2006 Microchip Technology Inc. DS39564C-page 275
PIC18FXX2
FIGURE 22-9: TIMER0 AND TIMER1 EXTERNAL CLOCK TIMINGS
TABLE 22-8: TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS
Note: Refer to Figure 22-4 for load conditions.
46
47
45
48
41
42
40
T0CKI
T1OSO/T1CKI
TMR0 or
TMR1
Param
No.
Symbol Characteristic Min Max Units Conditions
40 Tt0H T0CKI High Pulse Width No Prescaler 0.5TCY + 20 — ns
With Prescaler 10 — ns
41 Tt0L T0CKI Low Pulse Width No Prescaler 0.5T
CY + 20 — ns
With Prescaler 10 — ns
42 Tt0P T0CKI Period No Prescaler T
CY + 10 — ns
With Prescaler Greater of:
20 n
S or TCY + 40
N
— ns N = prescale
value
(1, 2, 4,..., 256)
45 Tt1H T1CKI High
Time
Synchronous, no prescaler 0.5T
CY + 20 — ns
Synchronous,
with prescaler
PIC18FXXX 10 — ns
PIC18LFXXX 25 — ns
Asynchronous PIC18FXXX 30 — ns
PIC18LFXXX 50 — ns
46 Tt1L T1CKI Low
Time
Synchronous, no prescaler 0.5T
CY + 5 — ns
Synchronous,
with prescaler
PIC18FXXX 10 — ns
PIC18LFXXX 25 — ns
Asynchronous PIC18FXXX 30 — ns
PIC18LFXXX 50 — ns
47 Tt1P T1CKI input
period
Synchronous Greater of:
20 n
S or TCY + 40
N
— ns N = prescale
value
(1, 2, 4, 8)
Asynchronous 60 — ns
Ft1 T1CKI oscillator input frequency range DC 50 kHz
48 Tcke2tmrI Delay from external T1CKI clock edge to timer
increment
2 T
OSC 7 TOSC —