Datasheet

 2001-2013 Microchip Technology Inc. DS39582C-page 185
PIC16F87XA
FIGURE 17-8: TIMER0 AND TIMER1 EXTERNAL CLOCK TIMINGS
TABLE 17-6: TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS
Param
No.
Symbol Characteristic Min Typ† Max Units Conditions
40* T
T0H T0CKI High Pulse Width No Prescaler 0.5 TCY + 20 — — ns Must also meet
parameter 42
With Prescaler 10 — — ns
41* T
T0L T0CKI Low Pulse Width No Prescaler 0.5 TCY + 20 — — ns Must also meet
parameter 42
With Prescaler 10 — — ns
42* T
T0P T0CKI Period No Prescaler TCY + 40 — — ns
With Prescaler Greater of:
20 or T
CY + 40
N
— — ns N = prescale value
(2, 4,..., 256)
45* T
T1H T1CKI High
Time
Synchronous, Prescaler = 1 0.5 TCY + 20 — — ns Must also meet
parameter 47
Synchronous,
Prescaler = 2, 4, 8
Standard(F)15——ns
Extended(LF)25 ——ns
Asynchronous Standard(F)30——ns
Extended(LF)50 ——ns
46* T
T1L T1CKI Low Time Synchronous, Prescaler = 1 0.5 TCY + 20 — — ns Must also meet
parameter 47
Synchronous,
Prescaler = 2, 4, 8
Standard(F)15——ns
Extended(LF)25 ——ns
Asynchronous Standard(F)30——ns
Extended(LF)50 ——ns
47* T
T1P T1CKI Input
Period
Synchronous Standard(F) Greater of:
30 or T
CY + 40
N
— — ns N = prescale value
(1, 2, 4, 8)
Extended(LF) Greater of:
50 or T
CY + 40
N
N = prescale value
(1, 2, 4, 8)
Asynchronous Standard(F)60——ns
Extended(LF) 100 — — ns
F
T1 Timer1 Oscillator Input Frequency Range
(oscillator enabled by setting bit T1OSCEN)
DC — 200 kHz
48 TCKEZ
TMR1 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.
Note: Refer to Figure 17-3 for load conditions.
46
47
45
48
41
42
40
RA4/T0CKI
RC0/T1OSO/T1CKI
TMR0 or TMR1