Datasheet

1999-2013 Microchip Technology Inc. DS39026D-page 249
PIC18CXX2
FIGURE 21-9: TIMER0 AND TIMER1 EXTERNAL CLOCK TIMINGS
TABLE 21-8: TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS
Note: Refer to Figure 21-4 for load conditions.
46
47
45
48
41
42
40
T0CKI
T1OSO/T1CKI
TMR0 or
TMR1
Param
No.
Symbol Characteristic Min Max Units Conditions
40 Tt0H T0CKI High Pulse Width No Prescaler 0.5TCY + 20 ns
With Prescaler 10 ns
41 Tt0L T0CKI Low Pulse Width No Prescaler 0.5T
CY + 20 ns
With Prescaler 10 ns
42 Tt0P T0CKI Period No Prescaler T
CY + 10 ns
With Prescaler Greater of:
20 n
S or TCY + 40
N
—nsN = prescale
value
(1, 2, 4,..., 256)
45 Tt1H T1CKI
High
Time
Synchronous, no prescaler 0.5T
CY + 20 ns
Synchronous,
with prescaler
PIC18CXXX 10 ns
PIC18LCXXX 25 ns
Asynchronous PIC18CXXX 30 ns
PIC18LCXXX 40 ns
46 Tt1L T1CKI
Low
Time
Synchronous, no prescaler 0.5T
CY + 20 ns
Synchronous,
with prescaler
PIC18CXXX 15 ns
PIC18LCXXX 30 ns
Asynchronous PIC18CXXX 30 ns
PIC18LCXXX 40 ns
47 Tt1P T1CKI
input
period
Synchronous Greater of:
20 n
S or TCY + 40
N
—nsN = 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
2T
OSC 7TOSC