Datasheet

Table Of Contents
PIC16F627A/628A/648A
DS40044A-page 144 Preliminary 2002 Microchip Technology Inc.
TABLE 17-9: TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS
Param
No.
Sym Characteristic Min Typ† Max Units Conditions
40 Tt0H T0CKI High Pulse Width No Prescaler 0.5T
CY + 20* ns
With Prescaler 10* ns
41 Tt0L T0CKI Low Pulse Width No Prescaler 0.5T
CY + 20* ns
With Prescaler 10* ns
42 Tt0P T0CKI Period Greater of:
T
CY + 40*
N
ns N = prescale
value (2, 4, ...,
256)
45 Tt1H T1CKI High
Time
Synchronous, No Prescaler 0.5T
CY + 20* ns
Synchronous,
with Prescaler
PIC16F62X 15* ns
PIC16LF62X 25* ns
Asynchronous PIC16F62X 30* ns
PIC16LF62X 50* ns
46 Tt1L T1CKI Low
Time
Synchronous, No Prescaler 0.5T
CY + 20* ns
Synchronous,
with Prescaler
PIC16F62X 15* ns
PIC16LF62X 25* ns
Asynchronous PIC16F62X 30* ns
PIC16LF62X 50* ns
47 Tt1P T1CKI input
period
Synchronous PIC16F62X Greater of:
T
CY + 40*
N
ns N = prescale
value (1, 2, 4, 8)
PIC16LF62X Greater of:
T
CY + 40*
N
——
Asynchronous PIC16F62X 60* ns
PIC16LF62X 100* ns
Ft1 Timer1 oscillator input frequency range
(oscillator enabled by setting bit T1OSCEN)
32.7
(1)
—kHz
48 TCKEZt
mr1
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.