Datasheet

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 T
T0H T0CKI High Pulse Width
No Prescaler
0.5TCY + 20* — — ns
With Prescaler 10* — — ns
41 T
T0L T0CKI Low Pulse Width No Prescaler 0.5TCY + 20* — — ns
With Prescaler 10* — — ns
42 TT0P T0CKI Period
20 or
Greater of:
T
CY + 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 T
T1L 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 T
T1P T1CKI input
period
Synchronous PIC16F62XA
20 or
Greater of:
T
CY + 40*
N
— — ns N = prescale
value (1, 2,
4, 8)
PIC16LF62XA
20 or
Greater of:
T
CY + 40*
N
———
Asynchronous PIC16F62XA 60* — — ns
PIC16LF62XA 100* — — ns
F
T1 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.