Microchip Technology DM164134 Hoja De Datos
PIC18FXX8
DS41159E-page 346
© 2006 Microchip Technology Inc.
FIGURE 27-10:
TIMER0 AND TIMER1 EXTERNAL CLOCK TIMINGS
TABLE 27-10: TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS
Param
No.
Symbol
Characteristic
Min
Max
Units
Conditions
40
Tt0H
T0CKI High Pulse Width
No prescaler
0.5 T
CY
+ 20
—
ns
With prescaler
10
—
ns
41
Tt0L
T0CKI Low Pulse Width
No prescaler
0.5 T
CY
+ 20
—
ns
With prescaler
10
—
ns
42
Tt0P
T0CKI Period
No prescaler
T
CY
+ 10
—
ns
With prescaler
Greater of:
20 ns or T
CY
+ 40
N
—
ns
N = prescale value
(1, 2, 4,..., 256)
(1, 2, 4,..., 256)
45
Tt1H
T1CKI
High Time
High Time
Synchronous, no prescaler
0.5 T
CY
+ 20
—
ns
Synchronous,
with prescaler
with prescaler
PIC18FXX8
10
—
ns
PIC18LFXX8
25
—
ns
Asynchronous PIC18FXX8
30
—
ns
PIC18LFXX8
50
—
ns
46
Tt1L
T1CKI
Low Time
Low Time
Synchronous, no prescaler
0.5 T
CY
+ 5
—
ns
Synchronous,
with prescaler
with prescaler
PIC18FXX8
10
—
ns
PIC18LFXX8
25
—
ns
Asynchronous PIC18FXX8
30
—
ns
PIC18LFXX8
TBD
TBD
ns
47
Tt1P
T1CKI
Input Period
Input Period
Synchronous
Greater of:
20 ns or T
CY
+ 40
N
—
ns
N = prescale value
(1, 2, 4, 8)
(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 T
OSC
—
Legend: TBD = To Be Determined
Note: Refer to Figure 27-5 for load conditions.
46
47
45
48
41
42
40
T0CKI
T1OSO/T1CKI
TMR0 or
TMR1