PIC16F870_13 Datasheet, PDF (130/172 Pages) Microchip Technology – 28/40-Pin, 8-Bit CMOS FLASH Microcontrollers

PIC16F870/871
FIGURE 14-8:
TIMER0 AND TIMER1 EXTERNAL CLOCK TIMINGS
RA4/T0CKI
RC0/T1OSO/T1CKI
40
41
42
45
46
TMR0 or
TMR1
47
48
Note: Refer to Figure 14-3 for load conditions.
TABLE 14-4: TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS
Param
No.
Sym
Characteristic
Min
Typ† Max Units Conditions
40* Tt0H
T0CKI High Pulse Width
No Prescaler
With Prescaler
0.5 TCY + 20
10
— — ns Must also meet
—
—
ns ^{parameter 42}
41* Tt0L
T0CKI Low Pulse Width
No Prescaler
With Prescaler
0.5 TCY + 20
10
— — ns Must also meet
—
—
ns ^{parameter 42}
42* Tt0P
T0CKI Period
No Prescaler
TCY + 40
— — ns
With Prescaler Greater of:
20 or TCY + 40
N
— — ns N = prescale value
(2, 4, ..., 256)
45* Tt1H
T1CKI High Time
Synchronous, Prescaler = 1
Synchronous, Standard(F)
Prescaler = 2,4,8 _Extended(LF)
0.5 TCY + 20
15
25
— — ns Must also meet
—
—
ns ^{parameter 47}
— — ns
Asynchronous Standard(F)
30
— — ns
Extended(LF)
50
— — ns
46* Tt1L
T1CKI Low Time
Synchronous, Prescaler = 1
Synchronous, Standard(F)
Prescaler = 2,4,8 _Extended(LF)
0.5 TCY + 20
15
25
— — ns Must also meet
—
—
ns ^{parameter 47}
— — ns
Asynchronous Standard(F)
30
— — ns
Extended(LF)
50
— — ns
47* Tt1P
T1CKI input period Synchronous
Standard(F) Greater of:
— — ns N = prescale value
30 or TCY + 40
(1, 2, 4, 8)
N
Extended(LF)
Greater of:
50 or TCY + 40
N
N = prescale value
(1, 2, 4, 8)
Asynchronous Standard(F)
60
— — ns
Extended(LF)
100
— — 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
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.
DS30569C-page 130
 2000-2013 Microchip Technology Inc.