PIC18F2455_07 Datasheet, PDF (386/430 Pages) Microchip Technology – 28/40/44-Pin, High Performance, Enhanced Flash, USB Microcontrollers with nanoWatt Technology

PIC18F2455/2550/4455/4550
FIGURE 28-9:
TIMER0 AND TIMER1 EXTERNAL CLOCK TIMINGS
T0CKI
T1OSO/T13CKI
40
41
42
45
46
47
48
TMR0 or
TMR1
Note: Refer to Figure 28-4 for load conditions.
TABLE 28-13: 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 T13CKI High Synchronous, no prescaler
0.5 TCY + 20 —
ns
Time
Synchronous, PIC18FXXXX
10
— ns
with prescaler _PIC18LFXXXX
25
—
ns VDD = 2.0V
Asynchronous PIC18FXXXX
30
— ns
PIC18LFXXXX
50
—
ns VDD = 2.0V
46 Tt1L
T13CKI Low Synchronous, no prescaler
0.5 TCY + 5 —
Time
Synchronous, PIC18FXXXX
10
—
with prescaler _PIC18LFXXXX
25
—
ns
ns
ns VDD = 2.0V
Asynchronous PIC18FXXXX
30
— ns
PIC18LFXXXX
50
—
ns VDD = 2.0V
47
Tt1P
T13CKI Input Synchronous
Period
Greater of: —
20 ns or
(TCY + 40)/N
ns N = prescale
value (1, 2, 4, 8)
Asynchronous
60
— ns
Ft1
T13CKI Oscillator Input Frequency Range
DC
50 kHz
48 Tcke2tmrI Delay from External T13CKI Clock Edge to Timer 2 TOSC 7 TOSC —
Increment
DS39632D-page 384
Preliminary
© 2007 Microchip Technology Inc.