Microchip Technology GPIODM-KPLCD Data Sheet
© 2009 Microchip Technology Inc.
DS39632E-page 391
PIC18F2455/2550/4455/4550
FIGURE 28-9:
TIMER0 AND TIMER1 EXTERNAL CLOCK TIMINGS
TABLE 28-13: TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS
Note:
Refer to Figure 28-4 for load conditions.
46
47
45
48
41
42
40
T0CKI
T1OSO/T13CKI
TMR0 or
TMR1
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)
value
(1, 2, 4,..., 256)
45
Tt1H
T13CKI High
Time
Time
Synchronous, no prescaler
0.5 T
CY
+ 20
—
ns
Synchronous,
with prescaler
with prescaler
PIC18FXXXX
10
—
ns
PIC18LFXXXX
25
—
ns
V
DD
= 2.0V
Asynchronous
PIC18FXXXX
30
—
ns
PIC18LFXXXX
50
—
ns
V
DD
= 2.0V
46
Tt1L
T13CKI Low
Time
Time
Synchronous, no prescaler
0.5 T
CY
+ 5
—
ns
Synchronous,
with prescaler
with prescaler
PIC18FXXXX
10
—
ns
PIC18LFXXXX
25
—
ns
V
DD
= 2.0V
Asynchronous
PIC18FXXXX
30
—
ns
PIC18LFXXXX
50
—
ns
V
DD
= 2.0V
47
Tt1P
T13CKI Input
Period
Period
Synchronous
Greater of:
20 ns or
(T
CY
+ 40)/N
—
ns
N = prescale
value (1, 2, 4, 8)
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
Increment
2 T
OSC
7 T
OSC
—