PIC16F631/677/685/687/689/690
FIGURE 17-8:
TIMER0 AND TIMER1 EXTERNAL CLOCK TIMINGS
T0CKI
40
41
42
T1CKI
45
46
49
47
TMR0 or
TMR1
TABLE 17-5: TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS
Standard Operating Conditions (unless otherwise stated)
Operating Temperature
-40°C ≤ TA ≤ +125°C
Param
Sym
No.
Characteristic
Min
Typ†
Max
Units
Conditions
40*
41*
42*
TT0H
TT0L
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*
46*
47*
TT1H
TT1L
T1CKI High Synchronous, No Prescaler
0.5 TCY + 20
15
—
—
—
—
ns
ns
Time
Synchronous,
with Prescaler
Asynchronous
30
0.5 TCY + 20
15
—
—
—
—
—
—
ns
ns
ns
T1CKI Low Synchronous, No Prescaler
Time
Synchronous,
with Prescaler
Asynchronous
30
—
—
—
—
ns
TT1P
FT1
T1CKI Input Synchronous
Period
Greater of:
30 or TCY + 40
N
ns N = prescale value
(1, 2, 4, 8)
Asynchronous
60
—
—
—
—
ns
48
Timer1 Oscillator Input Frequency Range
(oscillator enabled by setting bit T1OSCEN)
32.768
kHz
49*
TCKEZTMR1 Delay from External Clock Edge to Timer
Increment
2 TOSC
—
7 TOSC
—
Timers in Sync
mode
*
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.
© 2007 Microchip Technology Inc.
DS41262D-page 243
MICROCHIP [ MICROCHIP ]
