Datasheet

PIC24FJ256GB110 FAMILY
DS39897C-page 322  2009 Microchip Technology Inc.
FIGURE 29-3: EXTERNAL CLOCK TIMING
OSCI
CLKO
Q4 Q1 Q2 Q3 Q4
Q1
OS20
OS25
OS30 OS30
OS40
OS41
OS31
OS31
Q1 Q2 Q3 Q4
Q2
Q3
TABLE 29-13: EXTERNAL CLOCK TIMING REQUIREMENTS
AC CHARACTERISTICS
Standard Operating Conditions: 2.50 to 3.6V (unless otherwise stated)
Operating temperature -40°C  T
A  +85°C for Industrial
Param
No.
Sym Characteristic Min Typ
(1)
Max Units Conditions
OS10 F
OSC External CLKI Frequency
(External clocks allowed
only in EC mode)
DC
4
—
—
32
48
MHz
MHz
EC
ECPLL
Oscillator Frequency 3
4
10
12
31
—
—
—
—
—
10
8
32
32
33
MHz
MHz
MHz
MHz
kHz
XT
XTPLL
HS
HSPLL
SOSC
OS20 T
OSC TOSC = 1/FOSC — — — — See parameter OS10
for F
OSC value
OS25 TCY Instruction Cycle Time
(2)
62.5 — DC ns
OS30 TosL,
To s H
External Clock in (OSCI)
High or Low Time
0.45 x TOSC ——nsEC
OS31 TosR,
To s F
External Clock in (OSCI)
Rise or Fall Time
— — 20 ns EC
OS40 TckR CLKO Rise Time
(3)
— 6 10 ns
OS41 TckF CLKO Fall Time
(3)
— 6 10 ns
Note 1: Data in “Typ” column is at 3.3V, 25°C unless otherwise stated. Parameters are for design guidance only
and are not tested.
2: Instruction cycle period (T
CY) equals two 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 OSCI/CLKI pin. When an external clock input is used, the “Max.” cycle time
limit is “DC” (no clock) for all devices.
3: Measurements are taken in EC mode. The CLKO signal is measured on the OSCO pin. CLKO is low for
the Q1-Q2 period (1/2 T
CY) and high for the Q3-Q4 period (1/2 TCY).