PIC18FXX20
FIGURE 26-13:
TIMER0 AND TIMER1 EXTERNAL CLOCK TIMINGS
T0CKI
41
46
40
45
42
47
T1OSO/T1CKI
48
TMR0 or
TMR1
Note:
Refer to Figure 26-6 for load conditions.
TABLE 26-12: TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS
Param.
Symbol
Characteristic
Min
Max Units
Conditions
No.
40
Tt0H
T0CKI High Pulse Width
T0CKI Low Pulse Width
T0CKI Period
No Prescaler
0.5 TCY + 20
10
0.5 TCY + 20
10
—
—
—
—
—
—
ns
ns
ns
ns
ns
With Prescaler
No Prescaler
With Prescaler
No Prescaler
With Prescaler
41
42
Tt0L
Tt0P
TCY + 10
Greater of:
20 nS or TCY + 40
N
ns N = prescale
value
(1, 2, 4,..., 256)
45
46
Tt1H
Tt1L
T1CKI
Synchronous, no prescaler
0.5 TCY + 20
—
—
—
—
—
—
—
—
—
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
High Time
Synchronous, PIC18FXX20
10
25
30
with prescaler
PIC18LFXX20
Asynchronous PIC18FXX20
PIC18LFXX20
50
0.5 TCY + 5
10
T1CKILow Synchronous, no prescaler
Time
Synchronous, PIC18FXX20
with prescaler
PIC18LFXX20
25
30
TBD
Asynchronous PIC18FXX20
PIC18LFXX20
Synchronous
TBD
—
47
48
Tt1P
Ft1
T1CKI
Input
Period
Greater of:
20 nS or TCY + 40
N
ns N = prescale
value
(1, 2, 4, 8)
Asynchronous
60
DC
2 TOSC
—
50
7 TOSC
ns
kHz
—
T1CKI Oscillator Input Frequency Range
Tcke2tmrI Delay from External T1CKI Clock Edge to
Timer Increment
2003 Microchip Technology Inc.
Advance Information
DS39609A-page 327
MICROCHIP [ MICROCHIP ]
