Datasheet

© 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
1T
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
2T
CY Instruction Cycle Time
(1)
100
160
—
—
ns
ns
TCY = 4/FOSC, -40°C to +85°C
T
CY = 4/FOSC, +85°C to +125°C
3 TosL,
TosH
External Clock in (OSC1)
High or Low Time
30 — ns XT oscillator
2.5 — ns LP oscillator
10 — μs HS oscillator
4TosR,
TosF
External Clock in (OSC1)
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.