DSPIC30F5013 Microchip Technology Inc., DSPIC30F5013 Datasheet - Page 144

• Manufacturer Part Number: DSPIC30F5013
• Description: Dspic30f5011/5013 High-performance Digital Signal Controllers
• Manufacturer: Microchip Technology Inc.

dsPIC30F5011/5013
20.2
20.2.1
While coming out of Power-on Reset or Brown-out
Reset, the device selects its clock source based on:
a)
b)
Table 20-2 shows the Configuration bit values for clock
selection.
TABLE 20-2:
20.2.2
To ensure that a crystal oscillator (or ceramic resona-
tor) has started and stabilized, an Oscillator Start-up
Timer is included. It is a simple 10-bit counter that
counts 1024 T
clock to the rest of the system. The time-out period is
designated as T
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.
DS70116F-page 142
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
FRC w/ PLL 4x
FRC w/ PLL 8x
FRC w/ PLL 16x
HS
LP
FRC
LPRC
Note 1:
FOS<1:0> Configuration bits, which select one
of four oscillator groups, and
FPR<3:0> Configuration bits, which select one
of 13 oscillator choices within the primary group.
Oscillator Mode
2:
Oscillator Configurations
OSC2 pin function is determined by the Primary Oscillator mode selection (FPR<3:0>).
OSC1 pin cannot be used as an I/O pin even if the secondary oscillator or an internal clock source is
selected at all times.
INITIAL CLOCK SOURCE
SELECTION
OSCILLATOR START-UP TIMER
(OST)
OSC
OST
CONFIGURATION BIT VALUES FOR CLOCK SELECTION
cycles before releasing the oscillator
. The T
Primary
Primary
Primary
Primary
Primary
Primary
Primary
Primary
Primary
Primary
Primary
Primary
Internal FRC
Internal FRC
Internal FRC
Primary
Secondary
Internal FRC
Internal LPRC
OST
Oscillator
Source
time is involved every
FOS1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
1
FOS0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
1
0
20.2.3
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 oper-
ation. Returning to the faster main oscillator still
requires a start-up time.
FPR3
and
—
—
1
1
1
1
1
1
1
0
0
0
0
0
0
1
0
0
x
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
0
0
0
x
FPR1
—
—
1
0
0
1
1
0
0
0
0
1
1
0
0
1
1
1
x
© 2006 Microchip Technology Inc.
FPR0
—
—
1
0
1
0
1
1
0
0
1
0
1
0
1
0
1
0
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
I/O
I/O
I/O