
PIC16F946
DS41265A-page 244
Preliminary
2005 Microchip Technology Inc.
TABLE 19-5:
TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS
FIGURE 19-8:
USART SYNCHRONOUS TRANSMISSION (MASTER/SLAVE) TIMING
Param
No.
Sym
Characteristic
Min
Typ
Max
Units
Conditions
40*
TT0H
T0CKI High Pulse Width
No Prescaler
0.5 TCY + 20
—
ns
With Prescaler
10
—
ns
41*
TT0L
T0CKI Low Pulse Width
No Prescaler
0.5 TCY + 20
—
ns
With Prescaler
10
—
ns
42*
TT0P
T0CKI Period
Greater of:
20 or TCY + 40
N
—
ns
N = prescale
value (2, 4, ...,
256)
45*
TT1H
T1CKI High
Time
Synchronous, No Prescaler
0.5 TCY + 20
—
ns
Synchronous,
with Prescaler
3.0-5.5V
15
—
ns
2.0-5.5V
25
—
ns
Asynchronous
3.0-5.5V
30
—
ns
2.0-5.5V
50
—
ns
46*
TT1L
T1CKI Low
Time
Synchronous, No Prescaler
0.5 TCY + 20
—
ns
Synchronous,
with Prescaler
3.0-5.5V
15
—
ns
2.0-5.5V
25
—
ns
Asynchronous
3.0-5.5V
30
—
ns
2.0-5.5V
50
—
ns
47*
TT1P
T1CKI Input
Period
Synchronous
3.0-5.5V
GREATER OF:
30 OR TCY + 40
N
—
ns
N = prescale
value (1, 2, 4, 8)
2.0-5.5V
50 OR TCY + 40
N
——
ns
Asynchronous
3.0-5.5V
60
—
ns
2.0-5.5V
100
—
ns
FT1
Timer1 oscillator input frequency range
(oscillator enabled by setting bit T1OSCEN)
DC
—
37*
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.
Note:
121
120
122
RC6/TX/CK
RC7/RX/DT/
SCK/SCL/SEG9
SDI/SDA/SEG8