PIC16C62B/72A
FIGURE 13-9: TIMER0 AND TIMER1 EXTERNAL CLOCK TIMINGS
T0CKI
41
40
42
T1OSO/T1CKI
46
45
47
48
TMR0 or
TMR1
Note: Refer to Figure 13-4 for load conditions.
TABLE 13-5: TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS
Param
No.
Sym
Tt0H
Characteristic
T0CKI High Pulse Width
Min
Typ† Max Units
Conditions
40*
No Prescaler
With Prescaler
No Prescaler
With Prescaler
No Prescaler
With Prescaler
0.5TCY + 20
10
—
—
—
—
—
—
—
—
—
—
—
—
ns
ns
ns
ns
ns
ns
Must also meet
parameter 42
41*
42*
Tt0L
Tt0P
T0CKI Low Pulse Width
T0CKI Period
0.5TCY + 20
10
Must also meet
parameter 42
TCY + 40
Greater of:
20 or TCY + 40
N = prescale value
(2, 4,..., 256)
N
45*
46*
47*
Tt1H
Tt1L
Tt1P
T1CKI High Time
Synchronous, Prescaler = 1
0.5TCY + 20
—
—
—
—
—
—
ns
ns
ns
Must also meet
parameter 47
Synchronous,
Prescaler =
2,4,8
PIC16CXX
15
25
PIC16LCXX
Asynchronous
PIC16CXX
30
—
—
—
—
—
—
—
—
—
—
ns
ns
ns
ns
ns
PIC16LCXX
50
T1CKI Low Time
Synchronous, Prescaler = 1
0.5TCY + 20
Must also meet
parameter 47
Synchronous,
Prescaler =
2,4,8
PIC16CXX
15
25
PIC16LCXX
Asynchronous
PIC16CXX
PIC16LCXX
PIC16CXX
30
50
—
—
—
—
—
—
ns
ns
ns
T1CKI input period Synchronous
GREATER OF:
30 OR TCY + 40
N
N = prescale value
(1, 2, 4, 8)
PIC16LCXX
GREATER OF:
50 OR TCY + 40
N
N = prescale value
(1, 2, 4, 8)
Asynchronous
PIC16CXX
60
100
DC
—
—
—
—
—
ns
ns
PIC16LCXX
Ft1
Timer1 oscillator input frequency range
200
kHz
(oscillator enabled by setting bit T1OSCEN)
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.
1998 Microchip Technology Inc.
Preliminary
DS35008B-page 93
MICROCHIP [ MICROCHIP ]
