PIC16F688
FIGURE 14-7:
TIMER0 AND TIMER1 EXTERNAL CLOCK TIMINGS
T0CKI
40
41
42
T1CKI
45
46
48
47
TMR0 or
TMR1
TABLE 14-5: TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS
Param
Sym
Characteristic
Min
Typ† Max Units Conditions
No.
40* Tt0H
41* Tt0L
42* Tt0P
T0CKI High Pulse Width
No Prescaler
With Prescaler
No Prescaler
With Prescaler
0.5 TCY + 20
—
—
—
—
—
—
—
—
—
—
ns
ns
ns
ns
10
0.5 TCY + 20
10
T0CKI Low Pulse Width
T0CKI Period
Greater of:
20 or TCY + 40
N
ns N = prescale
value (2, 4,
..., 256)
45* Tt1H
46* Tt1L
T1CKI High
Time
Synchronous, No Prescaler
0.5 TCY + 20
15
—
—
—
—
ns
ns
Synchronous,
with Prescaler
Asynchronous
30
0.5 TCY + 20
15
—
—
—
—
—
—
ns
ns
ns
T1CKI Low
Time
Synchronous, No Prescaler
Synchronous,
with Prescaler
Asynchronous
Synchronous
30
—
—
—
—
ns
47* Tt1P
T1CKI Input
Period
Greater of:
30 or TCY + 40
N
ns N = prescale
value (1, 2, 4,
8)
Asynchronous
60
—
—
—
ns
Ft1
Timer1 oscillator input frequency range
DC
200*
kHz
(oscillator enabled by setting bit T1OSCEN)
48
TCKEZtmr1 Delay from external clock edge to timer
increment
2 TOSC*
—
7 TOSC*
—
*
These parameters are characterized but not tested.
†
Data in ‘Typ’ column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance only
and are not tested.
DS41203B-page 150
Preliminary
2004 Microchip Technology Inc.
MICROCHIP [ MICROCHIP ]
