PIC18F258 Datasheet, PDF (342/384 Pages) Microchip Technology – High Performance, 28/40-Pin Enhanced FLASH Microcontrollers with CAN

PIC18FXX8
FIGURE 27-9:
TIMER0 AND TIMER1 EXTERNAL CLOCK TIMINGS
T0CKI
T1OSO/T1CKI
40
41
42
45
46
47
48
TMR0 or
TMR1
Note: Refer to Figure 27-4 for load conditions.
TABLE 27-10: TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS
Param
No.
Symbol
Characteristic
Min
40 Tt0H T0CKI High Pulse Width No prescaler
0.5 TCY + 20
With prescaler
10
41
Tt0L
T0CKI Low Pulse Width
No prescaler
0.5 TCY + 20
With prescaler
10
42 Tt0P T0CKI Period
No prescaler
TCY + 10
With prescaler
Greater of:
20 ns or TCY + 40
N
45 Tt1H T1CKI
Synchronous, no prescaler
High Time _{Synchronous, PIC18FXX8}
with prescaler _PIC18LFXX8
0.5 TCY + 20
10
25
Asynchronous PIC18FXX8
30
PIC18LFXX8
50
46
Tt1L
T1CKI
Synchronous, no prescaler
Low Time _{Synchronous, PIC18FXX8}
with prescaler _PIC18LFXX8
0.5 TCY + 5
10
25
Asynchronous PIC18FXX8
30
PIC18LFXX8
TBD
47 Tt1P T1CKI
Synchronous
Input Period
Greater of:
20 ns or TCY + 40
N
Asynchronous
60
Ft1
T1CKI Oscillator Input Frequency Range
DC
48 Tcke2tmrI Delay from External T1CKI Clock Edge to
Timer Increment
2 TOSC
Max Units Conditions
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
TBD
—
—
50
7 TOSC
ns
ns
ns
ns
ns
ns N = prescale
value
(1, 2, 4,..., 256)
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns N = prescale
value
(1, 2, 4, 8)
ns
kHz
—
DS41159B-page 340
Preliminary
 2002 Microchip Technology Inc.