DSPIC30F6010 MICROCHIP [Microchip Technology], DSPIC30F6010 Datasheet - Page 140

• Manufacturer Part Number: DSPIC30F6010
• Description: High-Performance Digital Signal Controllers
• Manufacturer: MICROCHIP [Microchip Technology]

dsPIC30F6010
21.2
21.2.1
While coming out of Power-on Reset or Brown-out
Reset, the device selects its clock source based on:
a)
b)
The selection is as shown in Table 21-2.
TABLE 21-2:
21.2.2
In order to ensure that a crystal oscillator (or ceramic
resonator) has started and stabilized, an oscillator
start-up timer is included. It is a simple 10-bit counter
that counts 1024 T
oscillator clock to the rest of the system. The time-out
period is designated as T
every time the oscillator has to restart (i.e., on POR,
BOR and wake-up from Sleep). The oscillator start-up
timer is applied to the LP Oscillator, XT, XTL, and HS
modes (upon wake-up from Sleep, POR and BOR) for
the primary oscillator.
DS70119D-page 138
EC
ECIO
EC w/ PLL 4x
EC w/ PLL 8x
EC w/ PLL 16x
ERC
ERCIO
XT
XT w/ PLL 4x
XT w/ PLL 8x
XT w/ PLL 16x
XTL
HS
LP
FRC
LPRC
Oscillator Mode
Note 1: OSC2 pin function is determined by the Primary Oscillator mode selection (FPR<3:0>).
FOS<1:0> configuration bits that select one of
four oscillator groups.
AND FPR<3:0> configuration bits that select
one of 13 oscillator choices within the primary
group.
Oscillator Configurations
2: Note that OSC1 pin cannot be used as an I/O pin, even if the secondary oscillator or an internal clock
INITIAL CLOCK SOURCE
SELECTION
OSCILLATOR START-UP TIMER
(OST)
source is selected at all times.
CONFIGURATION BIT VALUES FOR CLOCK SELECTION
OSC
OST
Primary
Primary
Primary
Primary
Primary
Primary
Primary
Primary
Primary
Primary
Primary
Primary
Primary
Secondary
Internal FRC
Internal LPRC
cycles before releasing the
Oscillator
. The T
Source
OST
time is involved
FOS1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
1
Preliminary
FOS0
1
1
1
1
1
1
1
1
1
1
1
1
1
0
1
0
21.2.3
Enabling the LP oscillator is controlled with two
elements:
1.
2.
The LP oscillator is ON (even during Sleep mode) if
LPOSCEN = 1. The LP oscillator is the device clock if:
• COSC<1:0> = 00 (LP selected as main oscillator)
• LPOSCEN = 1
Keeping the LP oscillator ON at all times allows for a
fast switch to the 32 kHz system clock for lower power
operation. Returning to the faster main oscillator will
still require a start-up time.
FPR3
and
—
—
—
1
1
1
1
1
1
1
0
0
0
0
0
0
The current oscillator group bits COSC<1:0>.
The LPOSCEN bit (OSCON register).
FPR2
LP OSCILLATOR CONTROL
—
—
—
0
1
1
1
1
0
0
1
1
1
1
0
0
FPR1
—
—
—
1
0
0
1
1
0
0
0
0
1
1
0
1
 2004 Microchip Technology Inc.
FPR0
—
—
—
1
0
1
0
1
1
0
0
1
0
1
X
X
(Notes 1, 2)
(Notes 1, 2)
(Notes 1, 2)
Function
OSC2
CLKO
CLKO
OSC2
OSC2
OSC2
OSC2
OSC2
OSC2
I/O
I/O
I/O
I/O
I/O