
PIC16F627A/628A/648A
DS40044G-page 148
2009 Microchip Technology Inc.
TABLE 17-8:
TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS
Param
No.
Sym
Characteristic
Min
Typ
Max Units Conditions
40
TT0H
T0CKI High Pulse Width
No Prescaler
0.5TCY + 20*
—
ns
With Prescaler
10*
—
ns
41
TT0L
T0CKI Low Pulse Width
No Prescaler
0.5TCY + 20*
—
ns
With Prescaler
10*
—
ns
42
TT0P
T0CKI Period
20 or
Greater of:
TCY + 40*
N
—
ns N = prescale
value (2, 4,
..., 256)
45
TT1H
T1CKI High
Time
Synchronous, No Prescaler
0.5TCY + 20*
—
ns
Synchronous,
with Prescaler
PIC16F62XA
15*
—
ns
PIC16LF62XA
25*
—
ns
Asynchronous PIC16F62XA
30*
—
ns
PIC16LF62XA
50*
—
ns
46
TT1L
T1CKI Low
Time
Synchronous, No Prescaler
0.5TCY + 20*
—
ns
Synchronous,
with Prescaler
PIC16F62XA
15*
—
ns
PIC16LF62XA
25*
—
ns
Asynchronous PIC16F62XA
30*
—
ns
PIC16LF62XA
50*
—
ns
47
TT1P
T1CKI input
period
Synchronous PIC16F62XA
20 or
Greater of:
TCY + 40*
N
—
ns N = prescale
value (1, 2,
4, 8)
PIC16LF62XA
20 or
Greater of:
TCY + 40*
N
——
—
Asynchronous PIC16F62XA
60*
—
ns
PIC16LF62XA
100*
—
ns
FT1
Timer1 oscillator input frequency range
(oscillator enabled by setting bit
T1OSCEN)
—32.7(1)
—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.
Note 1:
This oscillator is intended to work only with 32.768 kHz watch crystals and their manufactured tolerances.
Higher value crystal frequencies may not be compatible with this crystal driver.