Datasheet

dsPIC33FJ12MC201/202
DS70265E-page 66 © 2007-2011 Microchip Technology Inc.
6.1 System Reset
The dsPIC33FJ12MC201/202 family of devices have
two types of Reset:
• Cold Reset
• Warm Reset
A cold Reset is the result of a POR or a BOR. On a cold
Reset, the FNOSC configuration bits in the FOSC
device configuration register selects the device clock
source.
A warm Reset is the result of all other Reset sources,
including the RESET instruction. On warm Reset, the
device will continue to operate from the current clock
source as indicated by the Current Oscillator Selection
(COSC<2:0>) bits in the Oscillator Control
(OSCCON<14:12>) register.
The device is kept in a Reset state until the system
power supplies have stabilized at appropriate levels
and the oscillator clock is ready. The sequence in
which this occurs is detailed below and is shown in
Figure 6-2.
TABLE 6-1: OSCILLATOR DELAY
Oscillator Mode
Oscillator
Startup Delay
Oscillator Startup
Timer
PLL Lock Time Total Delay
FRC, FRCDIV16,
FRCDIVN
T
OSCD ——TOSCD
FRCPLL TOSCD —TLOCK TOSCD + TLOCK
XT TOSCD TOST —TOSCD + TOST
HS TOSCD TOST —TOSCD + TOST
EC ————
XTPLL TOSCD TOST TLOCK TOSCD + TOST + TLOCK
HSPLL TOSCD TOST TLOCK TOSCD + TOST + TLOCK
ECPLL — — TLOCK TLOCK
SOSC TOSCD TOST —TOSCD + TOST
LPRC TOSCD ——TOSCD
Note 1: TOSCD = Oscillator Start-up Delay (1.1 μs max for FRC, 70 μs max for LPRC). Crystal Oscillator start-up
times vary with crystal characteristics, load capacitance, etc.
2: T
OST = Oscillator Start-up Timer Delay (1024 oscillator clock period). For example, TOST = 102.4 μs for a
10 MHz crystal and T
OST = 32 ms for a 32 kHz crystal.
3: T
LOCK = PLL lock time (1.5 ms nominal), if PLL is enabled.