
2000 Microchip Technology Inc.
Preliminary
DS41124C-page 137
PIC16C745/765
FIGURE 16-8: TIMER0 AND TIMER1 EXTERNAL CLOCK TIMINGS
TABLE 16-5:
TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS
46
47
45
48
41
42
40
T0CKI
T1OSO/T1CKI
TMR0 or
TMR1
Param
No.
Sym
Characteristic
Min
Typ Max Units
Conditions
40*
TT0H
T0CKI High Pulse Width No Prescaler
0.5 TCY + 20
——
ns
Must also meet
parameter 42
With Prescaler
10
——
ns
41*
TT0L
T0CKI Low Pulse Width No Prescaler
0.5 TCY + 20
——
ns
Must also meet
parameter 42
With Prescaler
10
——
ns
42*
TT0P
T0CKI Period
No Prescaler
TCY + 40
——
ns
N = prescale value
(2, 4,..., 256)
With Prescaler
Greater of:
20 or TCY + 40
N
——
ns
45*
TT1H
T1CKI High Time
Synchronous, Prescaler = 1
0.5 TCY + 20
——
ns
Must also meet
parameter 47
Synchronous,
Prescaler = 2,4,8
15
——
ns
Asynchronous
30
——
ns
46*
TT1L
T1CKI Low Time
Synchronous, Prescaler = 1
0.5 TCY + 20
——
ns
Must also meet
parameter 47
Synchronous,
Prescaler = 2,4,8
15
——
ns
Asynchronous
30
——
ns
47*
TT1P
T1CKI input period
Synchronous
Greater of:
30 or TCY + 40
N
——
ns
N = prescale value
(1, 2, 4, 8)
Asynchronous
60
——
ns
FT1
Timer1 oscillator input frequency range
(oscillator enabled by setting bit T1OSCEN)
DC
—
200
kHz
48
TCKEZTMR1 Delay from external clock edge to timer increment
2Tosc
—
7Tosc
—
* 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.
745cov.book Page 137 Wednesday, August 2, 2000 8:24 AM