Microchip Technology DM164134 Data Sheet
© 2006 Microchip Technology Inc.
DS41159E-page 343
PIC18FXX8
27.3.3
TIMING DIAGRAMS AND SPECIFICATIONS
FIGURE 27-6:
EXTERNAL CLOCK TIMING
TABLE 27-6:
EXTERNAL CLOCK TIMING REQUIREMENTS
OSC1
CLKO
Q4
Q1
Q2
Q3
Q4
Q1
1
2
3
3
4
4
Param
No.
Symbol
Characteristic
Min
Max
Units
Conditions
1A
F
OSC
External CLKI Frequency
(1)
Oscillator Frequency
(1)
DC
40
MHz
EC, ECIO oscillator, -40°C to +85°C
DC
25
MHz
EC, ECIO oscillator, +85°C to +125°C
DC
4
MHz
RC oscillator
0.1
4
MHz
XT oscillator
4
25
MHz
HS oscillator, -40°C to +85°C
4
25
MHz
HS oscillator, +85°C to +125°C
4
10
MHz
HS + PLL oscillator, -40°C to +85°C
4
6.25
MHz
HS + PLL oscillator, +85°C to +125°C
DC
200
kHz
LP oscillator
1
T
OSC
External CLKI Period
(1)
Oscillator Period
(1)
25
—
ns
EC, ECIO oscillator, -40°C to +85°C
40
—
ns
EC, ECIO oscillator, +85°C to +125°C
250
—
ns
RC oscillator
250
10,000
ns
XT oscillator
40
—
ns
HS oscillator, -40°C to +85°C
40
—
ns
HS oscillator, +85°C to +125°C
100
250
ns
HS + PLL oscillator, -40°C to +85°C
160
250
ns
HS + PLL oscillator, +85°C to +125°C
5
200
μs
LP oscillator
2
T
CY
Instruction Cycle Time
(1)
100
160
160
—
—
—
ns
ns
ns
T
CY
= 4/F
OSC
, -40°C to +85°C
T
CY
= 4/F
OSC
, +85°C to +125°C
3
TosL,
TosH
TosH
External Clock in (OSC1)
High or Low Time
High or Low Time
30
—
ns
XT oscillator
2.5
—
ns
LP oscillator
10
—
μs
HS oscillator
4
TosR,
TosF
TosF
External Clock in (OSC1)
Rise or Fall Time
Rise or Fall Time
— 20
ns
XT
oscillator
— 50
ns
LP
oscillator
—
7.5
ns
HS oscillator
Note 1:
Instruction cycle period (T
CY
) equals four times the input oscillator time base period. All specified values
are based on characterization data for that particular oscillator type under standard operating conditions
with the device executing code. Exceeding these specified limits may result in an unstable oscillator
operation and/or higher than expected current consumption. All devices are tested to operate at “Min.”
values with an external clock applied to the OSC1/CLKI pin. When an external clock input is used, the
“Max.” cycle time limit is “DC” (no clock) for all devices.
with the device executing code. Exceeding these specified limits may result in an unstable oscillator
operation and/or higher than expected current consumption. All devices are tested to operate at “Min.”
values with an external clock applied to the OSC1/CLKI pin. When an external clock input is used, the
“Max.” cycle time limit is “DC” (no clock) for all devices.