PIC18FXX20
26.4.3
TIMING DIAGRAMS AND SPECIFICATIONS
FIGURE 26-7:
EXTERNAL CLOCK TIMING (ALL MODES EXCEPT PLL)
Q4
Q1
Q2
Q3
Q4
Q1
OSC1
CLKO
1
4
3
4
3
2
TABLE 26-6: EXTERNAL CLOCK TIMING REQUIREMENTS
Param. No. Symbol
Characteristic
Min
Max
Units
Conditions
(1)
1A
FOSC
External CLKI Frequency
DC
DC
DC
0.1
4
4
4
5
25
40
4
MHz
MHz
MHz
MHz
MHz
MHz
MHz
kHz
EC, ECIO, PIC18FX620/X720
EC, ECIO, PIC18FX520
RC osc
XT osc
HS osc
HS + PLL osc, PIC18FX520
HS + PLL osc, PIC18FX620/X720
LP Osc mode
(1)
Oscillator Frequency
4
25
10
6.25
200
(1)
EC, ECIO, PIC18FX620/X720
1
TOSC
External CLKI Period
25
—
—
ns
ns
EC, ECIO, PIC18FX520
160
(1)
Oscillator Period
250
250
—
10,000
ns
ns
RC osc
XT osc
25
100
100
250
250
160
ns
ns
ns
HS osc
HS + PLL osc, PIC18FX520
HS + PLL osc, PIC18FX620/X720
25
—
µs
LP osc
(1)
2
3
TCY
TosL,
TosH
Instruction Cycle Time
100
30
2.5
10
—
—
—
—
ns
ns
µs
ns
ns
ns
ns
TCY = 4/FOSC
XT osc
LP osc
HS osc
XT osc
LP osc
External Clock in (OSC1)
High or Low Time
—
4
TosR,
TosF
External Clock in (OSC1) Rise
or Fall Time
20
50
7.5
—
—
HS osc
Note 1: Instruction cycle period (TCY) equals four times the input oscillator time-base period for all configurations except PLL. 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.
TABLE 26-7: PLL CLOCK TIMING SPECIFICATIONS (VDD = 4.2 TO 5.5V)
Param. No. Sym
Characteristic
Min
Typ†
Max
Units
Conditions
—
FOSC
Oscillator Frequency Range
4
—
10
MHz HS mode
—
—
—
FSYS
On-chip VCO System Frequency
PLL Start-up Time (Lock Time)
CLKO Stability (Jitter)
16
—
-2
—
—
—
40
2
+2
MHz HS mode
ms
%
t
rc
∆CLK
†
Data in “Typ” column is at 5V, 25°C, unless otherwise stated. These parameters are for design guidance only and are not
tested.
DS39609A-page 322
Advance Information
2003 Microchip Technology Inc.
MICROCHIP [ MICROCHIP ]
