
PIC18F1230/1330
DS39758D-page 290
2009 Microchip Technology Inc.
FIGURE 23-10:
TIMER0 AND TIMER1 EXTERNAL CLOCK TIMINGS
TABLE 23-11: TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS
Param
No.
Symbol
Characteristic
Min
Max
Units
Conditions
40
Tt0H
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
Tt0P
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
T1CKI High
Time
Synchronous, no prescaler
0.5 TCY + 20
—
ns
Synchronous,
with prescaler
PIC18FXXXX
10
—
ns
PIC18LFXXXX
25
—
ns
VDD = 2.0V
Asynchronous
PIC18FXXXX
30
—
ns
PIC18LFXXXX
50
—
ns
VDD = 2.0V
46
Tt1L
T1CKI Low
Time
Synchronous, no prescaler
0.5 TCY + 5
—
ns
Synchronous,
with prescaler
PIC18FXXXX
10
—
ns
PIC18LFXXXX
25
—
ns
VDD = 2.0V
Asynchronous
PIC18FXXXX
30
—
ns
PIC18LFXXXX
50
—
ns
VDD = 2.0V
47
Tt1P
T1CKI Input
Period
Synchronous
Greater of:
20 ns 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 TOSC
7 TOSC
—
Note:
46
47
45
48
41
42
40
T0CKI
T1OSO/T1CKI
TMR0 or TMR1