Datasheet

PIC18F2480/2580/4480/4580
DS39637D-page 444 © 2009 Microchip Technology Inc.
FIGURE 28-9: TIMER0 AND TIMER1 EXTERNAL CLOCK TIMINGS
TABLE 28-11: TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS
Param
No.
Sym Characteristic Min Max Units Conditions
40 T
T0H T0CKI High Pulse Width No prescaler 0.5 TCY + 20 — ns
With prescaler 10 — ns
41 TT0L T0CKI Low Pulse Width No prescaler 0.5 TCY + 20 — ns
With prescaler 10 — ns
42 T
T0P T0CKI Period No prescaler TCY + 10 — ns
With prescaler Greater of:
20 ns or
(TCY + 40)/N
— ns N = prescale value
(1, 2, 4,..., 256)
45 TT1H T13CKI High
Time
Synchronous, no prescaler 0.5 TCY + 20 — ns
Synchronous,
with prescaler
PIC18FXXXX 10 — ns
PIC18LFXXXX 25 — ns V
DD = 2.0V
Asynchronous PIC18FXXXX 30 — ns
PIC18LFXXXX 50 — ns V
DD = 2.0V
46 TT1L T13CKI Low
Time
Synchronous, no prescaler 0.5 TCY + 5 — ns
Synchronous,
with prescaler
PIC18FXXXX 10 — ns
PIC18LFXXXX 25 — ns V
DD = 2.0V
Asynchronous PIC18FXXXX 30 — ns
PIC18LFXXXX 50 — ns VDD = 2.0V
47 T
T1P T13CKI Input
Period
Synchronous Greater of:
20 ns or
(T
CY + 40)/N
— ns N = prescale value
(1, 2, 4, 8)
Asynchronous 60 — ns
F
T1 T13CKI Oscillator Input Frequency Range DC 50 kHz
48 T
CKE2TMR
I
Delay from External T13CKI Clock Edge to
Timer Increment
2 T
OSC 7 TOSC —
46
47
45
48
41
42
40
T0CKI
T1OSO/T13CKI
TMR0 or
TMR1