PIC18F2480 MICROCHIP [Microchip Technology], PIC18F2480 Datasheet - Page 33

• Manufacturer Part Number: PIC18F2480
• Description: 28/40/44-Pin Enhanced Flash Microcontrollers with ECAN Technology, 10-Bit A/D and nanoWatt Technology
• Manufacturer: MICROCHIP [Microchip Technology]

2.8
When PRI_IDLE mode is selected, the designated
primary oscillator continues to run without interruption.
For all other power managed modes, the oscillator
using the OSC1 pin is disabled. The OSC1 pin (and
OSC2 pin, if used by the oscillator) will stop oscillating.
In
SEC_IDLE), the Timer1 oscillator is operating and
providing the device clock. The Timer1 oscillator may
also run in all power managed modes if required to
clock Timer1 or Timer3.
In internal oscillator modes (RC_RUN and RC_IDLE),
the internal oscillator block provides the device clock
source. The 31 kHz INTRC output can be used directly
to provide the clock and may be enabled to support
various special features, regardless of the power man-
aged mode (see Section 24.2 “Watchdog Timer
(WDT)”, Section 24.3 “Two-Speed Start-up” and
Section 24.4 “Fail-Safe Clock Monitor” for more
information on WDT, Two-Speed Start-up and Fail-Safe
Clock Monitor. The INTOSC output at 8 MHz may be
used directly to clock the device or may be divided
down by the postscaler. The INTOSC output is disabled
if the clock is provided directly from the INTRC output.
If the Sleep mode is selected, all clock sources are
stopped. Since all the transistor switching currents
have been stopped, Sleep mode achieves the lowest
current consumption of the device (only leakage
currents).
Enabling any on-chip feature that will operate during
Sleep will increase the current consumed during Sleep.
The INTRC is required to support WDT operation. The
Timer1 oscillator may be operating to support a
TABLE 2-3:
 2004 Microchip Technology Inc.
RC, INTIO1
RCIO, INTIO2
ECIO
EC
LP, XT and HS
Note:
secondary
OSC Mode
Effects of Power Managed Modes
on the Various Clock Sources
See Table 4-2 in Section 4.0 “Reset”, for time-outs due to Sleep and MCLR Reset.
clock
OSC1 AND OSC2 PIN STATES IN SLEEP MODE
modes
Floating, external resistor should pull high
Floating, external resistor should pull high
Floating, pulled by external clock
Floating, pulled by external clock
Feedback inverter disabled at quiescent
voltage level
(SEC_RUN
PIC18F2480/2580/4480/4580
OSC1 Pin
and
Preliminary
real-time clock. Other features may be operating that
do not require a device clock source (i.e., SSP slave,
PSP, INTn pins and others). Peripherals that may add
significant
Section 27.2 “DC Characteristics: Power Down and
Supply Current”.
2.9
Power-up delays are controlled by two timers, so that
no external Reset circuitry is required for most applica-
tions. The delays ensure that the device is kept in
Reset until the device power supply is stable under nor-
mal circumstances and the primary clock is operating
and stable. For additional information on power-up
delays, see Section 4.5 “Device Reset Timers”.
The first timer is the Power-up Timer (PWRT), which
provides a fixed delay on power-up (parameter 33,
Table 27-10). It is enabled by clearing (= 0) the
PWRTEN configuration bit.
The second timer is the Oscillator Start-up Timer
(OST), intended to keep the chip in Reset until the
crystal oscillator is stable (LP, XT and HS modes). The
OST does this by counting 1024 oscillator cycles
before allowing the oscillator to clock the device.
When the HSPLL Oscillator mode is selected, the
device is kept in Reset for an additional 2 ms, following
the HS mode OST delay, so the PLL can lock to the
incoming clock frequency.
There is a delay of interval T
Table 27-10), following POR, while the controller
becomes ready to execute instructions. This delay runs
concurrently with any other delays. This may be the
only delay that occurs when any of the EC, RC or INTIO
modes are used as the primary clock source.
Power-up Delays
Configured as PORTA, bit 6
At logic low (clock/4 output)
Configured as PORTA, bit 6
At logic low (clock/4 output)
Feedback inverter disabled at quiescent
voltage level
current
consumption
OSC2 Pin
CSD
DS39637A-page 31
are
(parameter 38,
listed
in